Quote: "1 - I want to make a game like Unreal Tournament, what would be the best software for this?"
Neither, FPSC would seriously kill the 3DGM, (as everyone here will agree, that's not worth the money)...
You need a coding engine to make something like that...
Quote: "
2 - In FPS Creator, can i use my own models? (In .mdl format)"
No, they must be .X.......
Quote: "
3 - In 3D Game Maker, can i use my own models? (In .mdl format)
"
See question 2.....
I do recommend you get FPSC, as it has waay more entertainment in it than a game and is also cheaper than most games, but you won't make the next Halo/Half-Life/Bioshock?other awesome fps game of choice....
The 3DGM is widely accepted as the sort of thing 10 year olds use to make free games for your mates, it's no where near the quality of a commercial engine due to it's ease of use...
Hope I helped...