If this is a 3D game that lets you rotate and move the camera freely then I'd strongly suggest using low poly character models instead.
Despite looking better, collision detection on 3D characters is actually easier than it would be for 2D sprites - just a distance check really when you have a bullet position and can guage the limb positions on your characters. I mean can you imagine checking bullet collision between a point in 3D space and an image?
Plus, this is a biggie - drawing that many sprites will doom your project - there's simply too much work involved in hand drawing and animating those sprites, you'll soon get sick of that. Even rendered sprites can be a pain to generate and organise.
Van-B
The nature of Monkey was irrepressible!.
