do everything in Live, it'll be easier for you. there is no 'best way', the best way is the way you like best. there are several ways to accomplish things in Live, thats the beauty of it, there is no one set way of working. sometimes i chop and sequence directly on the track by adjusting the start/end points of the clips, sometimes i'll dump the samples in Sampler and do the same, if the samples are short i'll dump them in Impulse. also, doing everything in Live saves on HDD space, because it uses non-destructive editing, which means that no matter how many times you copy/paste a clip, it's still only referenceing that one audio clip, which will remain the same if you go back and play the original source file. the only time Live creates more wave files on your HDD is when you crop something or resample something to a new clip/track. other than that, you can take an old song on ur HDD, bring it in Live, copy/paste it a hundred times, chop'em up, filter, eq, reverse and all this sht, and the it's still only going to reference that one source file, which will remain unchanged no matter what you do to it in Live.
Trust me, I know what I'm talkin bout! check my history: