I REALLY wish i had more exp in modeling chars for gamez, because i would LOVE to help you, but im pretty sure all my chars come out really high poly, as i just sort of fiddle-fart until i get things right!!!
Good luck with your game tho, its looking very hype!!!
you may want to post this request in the BlenderChar forum. I’m sure that there is someone itching to do it.
Also, you might want to check some of the modding crews on Plant Half-Life, Planet Quake, etc. I’m sure that they could produce the models in Milkshape and hand them to you in dxf or vrml format. Once you have them, you can refine them as you please.