In the end, this is one of the dumbest things to focus on when making hip hop music. Hit/classic records have been made in this genre using mono 8bit 22khz samplerates on the MPC to save space. If you can't get quality out of even a 96kbps stereo sample...you need to find a new profession.
We hear so much about "quality" in a biz where when the rapper finally adds his vocals and sends the track to mastering it's gonna be molded to an entire different entity in the process anyway(could be good, could be bad). But IMO "quality control" is a cop out. People waste time focusing on it because they have no real contribution to making GOOD MUSIC which is all that ultimately matters when the right engineer can take a 2track 128kbps mp3 of your finalized song and make it sound better than average "producer" could with the tracked out files in the best "quality" possible.