I have heard reference to a "white" high pressure sodium lamp I believe from the UK / Europe  - like CMH but Sodium
I gather they are a warmer colour then CMH but "full spectrum" and used in retail environments
what is the proper name for them?
and where they sold in the US / 120V markets?

 They are called White SON in UK/EU

 We have them but it very rare here in the US
 As they have made a low voltage version of them.
  They were expensive and never really gain popularity here.

thanks I remember seeing "SDW" as an alternative term for them

The basic idea is that when you overdrive an HPS lamp, you are getting a pleasant very red rich warm light with high CRI. The price you pay is profoundly reduced efficacy and lifetime. Another problem is that the optimum power range is quite narrow and hard to achieve with conventional sodium choke ballasts over usual line voltage variations. Philips in Europe was the most successful with that tech (alongside with less known Japanese mfg's) getting ~85CRI at ~2500K color temp with their SDW-T and SDW-TG lamps. To achieve this, these lamps run on stabilized ballasts, either fully electronic (SDW-TG) or a choke plus TRIAC regulator (SDW-T). There is also another kind of such lamps, which are more likely to standard SON, but optimized for better CRI instead of peak efficacy. They are compatible with standard sodium ballasts and offer moderately improved CRI around about 60. Typically called SON Comfort and so.     

A little correction - a major problem with SDW-T / TG lamps and why they are run on special stablized ballasts is not with line variations but the effects of aging. As lamp age and get sputtered, lamp voltage increases, and also less enegy escapes as a light and more is dissipated inside the arc tube. That causes the arc tube to overheat, the light output further to decrease and color shift to pink  and next even to blue in very aged lamps. SDW ballast senses lamp voltage increase and reduces the power (compared to a new lamp, which is unusual) to get less light, but with stable color.

@RRK thanks for the "explainer" I knew they ran regulated ballasts but that was about it and they were popular for showing merchandise in stores
still interested in aquiring a setup but expect it to be HARD in Canada

SDW-TG lamp with electronic ballast should be agnostic about line frequency, so you can easily import one to play. Also, I heard about American ballasts for SDW-T lamps, but don't know about the details.

Also if you just want to get a feeling of SDW-T/TG and have a new lamp, you can run it on MH electronic ballast of corresponding power. I verified this is OK at least with new 100W SDW-T and slightly aged 50W SDW-TG with Tridonic and Philips ballasts. Not sure about 35W ones. Older lamps will run away without that special voltage/power compensation. See my album on SDW here: https://www.lighting-gallery.net/gallery/thumbnails.php?album=7723

@RRK a lot of listing show 50/60 HZ 220-240 so they spec 60 cycle and likely are a DC switching type of affair so would need to wire in a 220V outlet to run one 

Sure, but beware of unscrupulous sellers that may sell some gear as double frequency which in practice isn't. Generally, electronic ballast for these lamps by Philips (a large single black brick) shall work at any line frequency, while a magnetic combo (a classic looking choke + a small electronic stabilizer gizmo) like on my picture would not. The electric power involved is not high, to get 220/230V volts you can use any suitable autotransformer. As far as I understand these things works, magnetic combo can be rather easily adjusted to work OK on 60Hz, too, but this better to be verified with special tools like oscilloscope.

In theory the "gizmo with a magnetic part and a small electronic regulator" can be designed to operate at both frequencies. Inside it is nothing else than a triac dimmer running a series choke ballast, the "dimmer" being controlled so the lamp arc current and voltages are where they are supposed to be. So even when the choke changes its impedance, the "diommer" part should be able to compensate, provided the choke is not too high inductance so the "dimmer" get maxed out still without reaching the required current.
So very likely a "240V/60Hz" gear has a very high chance to operate at 230V/50Hz correctly, as 60Hz operation dictates lower inductance so at 50Hy the dimmer may just cut back a bit more.
But a "230/50Hz" may not be able to reach the required power when operated at 60Hz, as the inductor there may be way too large.

But the question is, whether the "dimmer" range isn't limited from the minimum angle too...

@RRK the ballasts I have looked at are the "black box" phillips ones NOT the 2 part choke+controller and have listed 50/60 right on the spec sheet in the photo

@Medved: You can see real world oscillograms on my page, yes the dimmer can go to almost zero firing degree. You can see, with a new lamp it chops relatively small part of line half-period, may be 1/10 or even less, and the lamp runs at almost full possible power. That means that when the circuit will be brought into 60Hz part of the world) where choke impedance will be 1.2 times higher, there will be not enough slack to compensate and lamp will run about 10% underpowered.

To complete the list of these white light sodium lamp is that Philips also mare for a brief period a range of SON-T DECO lamps intended for normal (high voltage) Sodium lamp gear. They came in 150,250 and 400W. Philips listed them only for around two years for the international market and a a little bit longer for France. Their CCT is 2500K and CRI of over 80, same as for SDW lamps. 

White SON is indeed the most common denomination for those lamps, with Philips's SDW being the most successful platform. As others have mentioned above, there was also the SON-T Deco from the same manufacturer. Also, there is the K-Hica from Matsushita, the NHT SDX from Iwasaki (both from Japan), the GE LU SP28 (USA), and the Osram DSX-T Colorstar (Germany). Note that the last two lamp types used pulsed power to turn the orange light of a mercury-free HPS discharge to a pleasant warm white light.

On the pulsed current white lamp topic - I think that I can feel that SDW lamps operated on inductive ballast (current crest 1.41) *might* have slightly better color than ones operated on electronic ballast. It may be a result of self-suggestion easily too, for sure, and I regrettably did not verify that electronic ballast for SDW indeed generates squarewave current with current crest of 1.