Yep, Im running a GF FX5200 128mb as well and it works great. I get around 60-70 FPS in the air and 40 or so near the ground. Then again, I also have a 3.2GHz processor and 2gigs of RAM, so your's (Eagle) will very much differ.
Id go with gunner and just try it out. If it doesnt work, look into a new video card. If you're on a budget, I'd go with the Fx5200. Its fairly cheap and will run AH2 no sweat.