You have a GFP-555 preamp, two GFA-555 power amp, a GFS-3 speaker selector and two pair of speakers and want to connect all these thing up?
Please tell us how you want it to be setting up, play both pair of speakers at the same time? or you want to listen to one pair of speaker at a time?
By the way, if you want to play both pair of speakers at the same time, and bridging the amp as mono blocks and connect two speakers to each mono block is NOT advisable!