you have three matters there:
as for noise, if you haven't already, search on ground loop and eliminate them in your system. your qsc amps are good amps and should not make any humm.
as for measurement, one option is an all in one kit, such as omnimic from parts express. another option is a calibrated mic, an external 'soundcard' device, and software. there are calibrated behringer mics such as the ecm8000 if you feel that your rs meter with correction file isn't good enough for eq'ing bass. the mic requires phantom power, which can be provided independently or from an external sound card that includes it such as the M-Audio MobilePre USB. for software, rew (room eq wizard) is free. if you stick with your rs meter, then i think a behringer uca202 and the rew software is all that you need, but that needs to be confirmed.
as for eq, there are several solutions, but since i'm as confused as anyone about which software goes with which minidsp and which one is ideal for ht setup, somebody else can weigh in there.
good luck with it all. it really isn't as complicated as it sounds.