We cut ours about 15% down from stock, the dyno has shown us an average of 9-13 hp at the rear wheels, will you "feel" it that much in a QC? it really depends on the person, its def not something that will knock your pants off LOL , but there is small gains.
as far as oem pulley slithering, I can have them done, right now the machinest has in line the tb's , shifters, and some hood struts that should be at the anodizer, but we do have plans to do the complete pulley set again. and we do a couple sizes of alternator pulleys, we have just a few of those left , been doing those for the guys with high amp stereos.
the balancer, man all I will use and trust so far is the ATI