CPU Usage

I'm building a patch that plays back some samples. Some I want to loop, like a drum riff, and others I want to just play back a single hit, like some extra percussion for the drums.

My question is: Which object should I use for looping playback and which should I use for the hits? I understand buffer~ loads the sample into the RAM and that the sfplay~ reads it right off the disc, but if I've got multiple loops playing and me adding hits every now and then (on top of changing effects) what is the most efficient method for my computer? (iBook G4 OS 10.5.7 Power PC, 1.2GHz 1.25GB... old i know but its all I got)