Good find, though. Did you get the "Black Dog" or the "Smoke on the Water?"
I'm not sure if the 7-sp GPX shifters will run that 6-sp Shimano rear, wish I knew. I know the spacing is a little off with the 7-sp Shimano vs. the 7-sp GPX. There may be someone here with a 7-sp GPX freewheel. The other option is to use 6-sp Shimano shifters. The FD and RD anc cranset will work fine. For the hoods, that's a toughie, as the eBay seller of those things they're priceless.... I've no idea if the Cane Creek aero hoods will work or not. Those are nice calipers, too, with the hidden springs.