I like to just sample drums into the SP, then from the SP into the MPC. That way you get the SP crust, but then you can use the MPC's envelope settings, layering, and sequencer.
When you sample out of the SP into the MPC, mess with the SP's output/filter setting (menu#17) to get the best filter setting for each different drum sound. The MPC has a filter too, but the SP filters can sound SWEET.
Also, mess with the trick where you sample with the turntable on 45rpm, then pitch the sample back down in the SP. This will in effect give you more sampling time, but plus it makes the sound of the samples extra crusty and grainy (which can be killer on snares, horns, etc.)
Some guys will use the MPC to trigger the SP via MIDI which is fine, but you can only trigger the SP's samples at one pitch....and when you trigger the SP externally, the pitch can't be set with the normal tune setting. You have to go into the menu and set it (MIDI init tune or something like that).
I would give the SP a year or so before you decide to sell it. It's a real fun machine to use by itself too once you get into it. The SP is a somewhat hard machine to come by so don't take it lightly. Plus, the way you came into it, all cheap and brand new, suggests fate.
