Halo MOD, where you take all the multiplayer maps from Halo and put them in your own MOD. You could reskin the players to be the Cyborg superhuman we all know. If you guys do make a MOD off of this, then you should really take it off of TFC. TFC is a great game, better than CS in my view. although, even if you do this, there would be no way to make a banshi. Ghosts might be possible, and you would have to combine your gun onto your vehical entity to create the warthog. If you completed it, valve would not buy it, because it would be complete plaugerizm, making all that I wrote completly pointless.
Sure, make your map, but do not make a mod out of it. It is illeagle (Sick bird).