well, as Trade Gothic is a Linotype face, and their EULA prohibits modifications, you may have to contact them to arrange for the changes you need.

ParaType has a cyrillic version, if not they're the best at doing customizations.
If they're not available, I'd have to recommend considering P22 to do a custom job for you. :^D>

Drawing a Cyrillic counterpart from scratch cannot be prohibited.
Joshua, what's your budget, and your timeframe?

hhp

ParaType has a Cyrillic version of News Gothic on their site. (Linotype's Trade Gothic was based pretty closely on ATF's News Gothic.)

(I would provide a direct link, but the site's use of frames makes it impossible.)

http://www.paratype.com/pstore/default.asp?search=News+Gothic&fcode=PT_NGT