I hope with all the attention they've been getting recently we see these two games fairly soon. Like some of you I also tried to install both of these games recently. Heavy Gear 1 without the 1.1/1.2 patches works fine. Heavy Gear 2 has the same culling issues as everyone else. From digging around I've come to the conclusion that that is caused by the way new hardware handles Z-buffering. That is also why it still works on an old X800. Here's to hoping we see these games before the world ends. Either way, I'll be playing HG 1!
Edit: I just looked at the 1.1 and 1.2 patch notes. They both have to do with Z-buffering stuff. I wonder if we can't use Application Compatibility Toolkit to apply some fixes for that. I remember scrolling through the list and there was something about DirectX faking or DirectDraw forcing in there.
Edit 2: Could you guys maybe post the errors you find when you run Heavy Gear with patches applied and which patches you ran?
Edit 3: I started messing around in the Application Compatibility Toolkit and found a fix for Heavy Gear 2's culling issue. Full details here:
http://www.gog.com/en/forum/general/heavy_gear_2_culling_fix