First Read, this is only my opinion, but you gonna get a lot of feedback on it...
first do what you can afford
2 find some people you have locally or at a music store to go see if you can work out on their gear
Ok here you go man, if you want more versatility and Sound like cats above they are probably using a mixture, I read an article a loooooong time ago in the late 90's of timbo fucking with fruity loops experimentally at the same time he had all of his gear asr, triton etc, but remember especially since they have the luciano$$$ people that have been around in this game for awhile are not gonna just be sitting around fucking with a bootleg copy of fruity loops like its the only thing they can afford to get the sound they want and cursing all hardware users bragging about how much better their beats are LOL, the cats you mentioned above have primo setups and can probably afford any piece they want, in Real form not a vst imitiation that comes strikingly close, and furthermore if you just want to stay sampling and never doing any other serious instrumentation without frustration, delay, polyphony etc....you better think of getting HARD gear and an mpc...but its how you integrate all of that to get the maximum...with fruity all of that is put together...no cables, no hard mixer to toggle, no noise to contend with, no having to think hard about midi channels and assignments...just a whole nother skill level of producing is left out....just sit down and make some beats and get grammies and collect checks...LOL JK ....but not that one is better than the other, its what do you want to do and how versatile to you want to be.