Oh, I wish I had known about these guys before I paid a ridiculous amount of money on some half-used Squat sprues on ebay!
It's a company called Steel Crown, and they make a bunch of 6mm sci-fi stuff, a lot of which could probably be used for Epic Armageddon. Very reasonably priced, I've only had a quick look but it seems like they have stuff that could count as IG, Squats and Necrons to name but 3.
Well worth a look in any case I reckon if you're building an epic forcehttp://www.exoduswars.com/
Here are some pics from the range:
Some of the 'space dwarf' Kharazi
Very nicely detailed for 6mm
These guys would serve as IG: