Thanks guys, helpful stuff! Evoke's tutorials and Innovine's post have really put me in the right direction.
Unfortunately, it doesn't look like Ableton's Sampler has an option to spread a sample across its keyrange without pitch-shifting it chromatically, with the keyfollow controlling sample start position - like your MPC's slice function
It's a shame because it's got some really nice modulation envelopes and filters that I was getting some cool sounds with. In Evoke's tutorials, he chooses his start positions manually which I'll probably do anyway... But since I'm a gearslut, now I'd like to hear some opinions about sampler VSTs that have a similar sample playback option... Kontakt? Alchemy? What are your opinions?
Thanks again, everyone. I'm on the right track.