making a remix

Yo! I want to do a remix and I have my beat and a couple of acapellas of the artist i would like to put on the beat. My problem is: how to adjust the beat to a particular tempo? Because I know the tempo of the original song and I want to have my beat in the same tempo- do I have to change the tune of the samples of my beat (i've got it chopped into 32 pieces) and check which tune fits best? or is there any different and maybe a better way(or maybe there is some kind of a pattern?)?? And finally when I manage to get my beat to the same tempo as the original song and I try to put the acapella I realize that a different acapella of this artist would be better to this beat, so I try to adjust my beat to the tempo of the different song and I repeat the whole procedure that I described above. It's a little bit tiring so please help. PEACE!!

you could use a software like wavelab(win) or Peak (Mac) to adjust the tempo of the song you sampled for the beat, without changing the pitch. You can also load all the individual sliced samples and adjust the tempo for each one of them. I think this is the only way to do it.
Keep in mind that there is always a loss of quality if you timestrech without changing the pitch...

Best bet is to start over with samples that fit the correct tempo. If you have to stretch it too much it aint gonna sound good. Before you start, keep in mind the vibe of the a capella and create a beat to match it. In this case you dont have the luxury of an MC rappin to fit your beat. You have to make a beat to fit the lyrics.