Anybody know of a online store or site selling 100w Coated Medium base ED-17 mercury vapor lamp of GOOD QUALITY, In my area these are very hard to get now, only ones I can find are either clear Caster brand (china) or the Westinghouse (china) coated ones that may as well just be considered "inside frost" as the phosphor coating does absolutely nothing to manipulate or improve the green/blue color. If anybody knows where I could find one it would be much appreciated.

I don't know where you'll find ED-17, but there are some A-23 on ebay here. Depending on your application, they may not fit, though.

Here is an ebay link to some Sylvania 100 watt mercury lamps. I have no idea what quality the phosphors are, or where they were made, though.

There are the standard Euro (240v countries) 125w E27 mercs with 1.15A arc current. Maybe one of those will work ? Will the E27 base fit the E26 socket ? They appear to work fine on the Euro 70w HPS ballast too

Those are China too now. Few years ago they were made in EU so if you find a NOS one itll be good. (Maybe the China ones are good too, they apppear the same but they dont exist for long enough to tell the quality)