I have an A500 with a VXL-30 accelerator, Megachip, and Indivision ECS, among other things, crammed in there. As long as you don't plan on putting the metal top shield back on they all fit fine, I just had to use one additional socket to raise the accelerator up a bit, and a bit of very thin foam between the bottom of the accelerator and the top of the Megachip, and between the top of the accelerator and bottom of the keyboard. System works great, 100% stable, no heat issues, although I have considered adding a small fan at some point.
Good luck with your project!
