Agree with soix, don't skimp on the center channel! (I will add subwoofer to that tho...)
As far as pre/pro - amp, I am very pleased with Outlaw Audio 976 pre/pro and their model 7000 power amp (1698.00 on their website for the combo!) which will leave plenty of $$ leftover for quality speakers/interconnects/speaker cables. Good luck and enjoy the journey!