You need to get PROPELLERHEAD REASON to make your samples and the REWIRE it with a program such as CUBASE SX, ADOBE AUDITION OF ABLETON LIVE 4 OR 5.
REASON is one of the best software sequencers out there today. at the studio where i engineer, we use REASON and REWIRE it with STIENBERG NUENDO.
FL STUDIO 5 is also a very good but underated sequencer. It can also record audio, which REASON cannot yet do. it is one of the best remixing tools available, although it cannot come close to ABLETON'S LIVE 4/5.
If you have a midi sequencer, ie REASON, and a audio sequencer, ie CUBASE or NUENDO then you can do some great stuff. Just remember to keep your vocals at around -6 db, as a lot of clipping will occur; this clipping is not easily fixed, not even with the best software and plugins, (ie PROTOOLS).
If you have any other questions you can email me @ morrisnoblejr@yahoo.com and i'll be sure to get back to you A.S.A.P.