I am willing to help any fellow collectors.  I can get anyone who is interested a 250 Watt GE M250R2 with a Glass Drop-Lens through the distributor I bought mine at.
The Catalog Number is M2RR25S0A2GMS3358.  I paid $179.00 + Tax ($196.19).  The only extra you would have to pay is the shipping charges.  So, if you have trouble getting one of these Luminaires, and would like one, I can help you out.  You can choose your own Catalog number through this page right here.

 http://www.gelighting.com/LightingWeb/na/images/OLP2934-GE-M250R2-M2RR-Roadway-HID-Data-Sheet_tcm201-61507.pdf (M250R2)
 http://www.gelighting.com/LightingWeb/na/images/olp2937-ge-street-lighting-201sa-unit-pack-sam-roadway-hid-datasheet_tcm201-61492.pdf (201SA)
 http://www.gelighting.com/LightingWeb/na/images/OLP2925-GE-M400-MSRL-MSRA-Roadway-HID-Data-Sheet_tcm201-61516.pdf (M400)

Just let me know if you want 50, 70, 100, 150, 200, 250 watt, and if you want Multi-Volt Ballast (120/208/240/277) or if you want only a specific volt ballast (may be cheaper), and the less wattage may be cheaper, but the price I have listed is for the catalog number I ordered.  If anyone is interested, let me know what you would like, and I will create an eBay listing specific to what you want, and that way we will have a legal binding contract (to make you, the buyer, more comfortable and would know I'm not trying to jack your money, lol).  Just an FYI, it would take 3-4 weeks to come in after I order it, as it comes straight from the factory.  

Anyone who wants a 201SA Hood (70, 100, 150 watt) I can also get that for $$69.95 + Tax ($76.25).  The 201 Hood Unit Pack would come with a 201 Hood, Refractor, and GE Bulb.  Again, price may vary if you get a lesser wattage.  

I am just posting this to help my fellow collectors who may be interested in getting these items, but have no other way to get them.  From the time you tell me your intent, it could take up to 5-6 weeks, as I have to place the order, and it has to come in to my distributor, and then I have to send it to you.  I would send it via UPS, and I am not sure how much shipping would cost, but for ground, it shouldn't be no more than $20.00.

http://www.lighting-gallery.net/gallery/displayimage.php?pos=-110002 (This is what I have, and is the catalog number I ordered/Price I paid)

I forgot to add that the prices I listed are for 250W (Cobrahead) and 100W (NEMA Head) High Pressure Sodium.  PSMH may be more expensive or cheaper on the Cobra Head, and HPS is the only type available for the 201SA.

I do need some refractors for my MV version of GE SA201.  Let me  how much  those run me?
 

I do need some refractors for my MV version of GE SA201.  Let me  how much  those run me?
 

For just a refractor, (Latch Type), The Standard Price is $50.01.  I can't order just a replacement refractor from the distributor.  At $50.01, you're better off ordering the whole fixture/refractor/bulb for $69.95 + Tax (The refractor is practically free at that point).  You are looking for a GE V5AL Refractor, BTW Type V Acrylic Lens

Can you explain more about the different types of ballasts & voltage options ? As in, what is the difference between the few 240V 60Hz options ?

Can you explain more about the different types of ballasts & voltage options ? As in, what is the difference between the few 240V 60Hz options ?

Not sure what you mean there.  Can you explain in a different way?  The links I provided to the data sheets should answer your questions. 

Can you explain more about the different types of ballasts & voltage options ? As in, what is the difference between the few 240V 60Hz options ?

I just read the data sheet, and I see what you're talking about now.  That is something you might have to email GE about and ask them through their customer service or technical support team.  I don't know the difference between them.  Personally, I would buy the multi-volt ballast (120/208/240/277).  With that one, the red wire coming from the PE Receptacle can be connected to one of 4 tabs (whichever tab your desired voltage is)

Are there setups where for example the gear is connected between 2 Phases at 240V, the PC switch one of them, and the PC itself is powered by 120V (it gets a Neutral) - stuff like that ?

Or are modern PC's multivolt by themselfes ?

Are there setups where for example the gear is connected between 2 Phases at 240V, the PC switch one of them, and the PC itself is powered by 120V (it gets a Neutral) - stuff like that ?

Or are modern PC's multivolt by themselfes ?

I am not very familiar with the  M400 itself.  I haven't studied it as much as the M250 and the 201SA.  However, I would say you are correct.  I just don't know which one is which.  I can give you a contact at General Electric though who can probably answer your questions.  

stephen.carson@ge.com  His name is Stephen Carson, and he is a technical support guy.  Once you get a response back from him, let me know if you are interested, and I will order whichever catalog number you are after.  Mr. Carson does not do orders, I have to get them through the distributor.  However, there is a suggested catalog number for multi-volt applications on the data-sheet.  

MSRL40S0A22RMS3 for 400 Watt HPS (The "0" stands for 120/208/240/277V Ballast)  (M400R3)
MSRL25S0A22RMS3 for 250 Watt HPS (This one and the one above are M400R3 with drop lens)
M2RR25S0A2GMS3358 for 250 Watt HPS (M250R2 with glass drop lens)

Here are the data sheets again, in case you would like to print them out.

M400R3 (MSRL and MSRA) - http://www.gelighting.com/LightingWeb/na/images/OLP2925-GE-M400-MSRL-MSRA-Roadway-HID-Data-Sheet_tcm201-61516.pdf
M250R2 (M2RR) - http://www.gelighting.com/LightingWeb/na/images/OLP2934-GE-M250R2-M2RR-Roadway-HID-Data-Sheet_tcm201-61507.pdf
201SA (SAM201) - http://www.gelighting.com/LightingWeb/na/images/olp2937-ge-street-lighting-201sa-unit-pack-sam-roadway-hid-datasheet_tcm201-61492.pdf

The 201SA is the least complicated to order.  

Also, don't quote me on this, but I believe that the 'E' (MSRL40E0A22RMS3) is Pulse Start Metal Halide, and I believe it can run both HPS and Pulse Start MH.  I believe it has a Red/White NEMA Label, and I have seen them in my town running HPS lamps and PF-400 Power Flood Luminaires running both HPS and Metal Halide.  I would do more research before ordering that myself though.  I can tell you that while the M250R2 with the catalog number I listed is $179.00 + Tax ($200.00 rounded off), the M400R3 may be substantially more expensive, given that it has more capabilities and more options.  If you order an M400R3 with basically the same options as the M250R2, it may not be too much more expensive though.