Top level freestyle and top level slalom performance is rather hard to combine into one board ad mmoritz writes. Kombats are fast and you can bust freestyle moves on them, but in each discipline a specialized board will work better of course. If you're not necessarily need that type of top performance the Kombat wil be a good choice. Its a very all round type of board.
The Futuras are also freeride booards, but they will not be so good for freestyle since they lack the ability to mount a single footstrap rear. Last years S-type could be an option. Fast boards that also can be used with a single rear strap. If you lean more towards freestyle, last years Flare could be an option too. That board got a really fast slalom rocker. Due to softer rails and only a single strap rear it will not be as fast as a slalom board, but with the right fin it can be rather fast still (08 Flare have a different rocker - more freestyle specific).
So, overall, the Kombat is the best compromise between fun/tricks and speed/blasting.