Look at QFusion, it uses Quake 3's media. Of course you'll have to have a full install of Q3 for it to work. I ain't ripping stuff off anyone. I'm using what people already have. 
My game is a very crazy hybrid RTS, you've got bits of all sorts of games.
- It's a shooter because you can control units (vehicles, infantry whatever...) directly (you will have both third person and first person views)
- It's a strategy game because you can build a base and there's a top down view that's fully 3D (so no my game isn't like BattleZone!!) The camera is more like Dark Reign 2 than say, Generals. Generals camera sucks...
- It's an RPG because units aren't units. They are individual characters that evolve as they fight. Characters also have personalities, units are generic. Characters fight differently, use different weapons in effect make the game a heck of alot better. Instead of making a whole horde of specific units, you can make Characters that specialise as they find out what they 'like' (ie. Characters have EMOTIONS, GOALS AND PRIORITIES!)
Eventually i hope to have all original everything, ie. no Q3 stuff.
I'd never rip off any art
