MDI you can have really detailed models that aren't high polygon or huge texture sizes, and it would run great, consider getting Texture Maker, it's a really good program for making textures:
http://www.i-tex.de/news.phpat least try out the demo and you'll see what i mean. when the game gets to the polish stage just remember that if it's running great on the pc you are going for as a minimum pc, then you can add more effects, and increase model skins and polys
