right now using apogee centaur speakers, citation 7.0 processor and a citation 7.1 4- channel amp. Considering adding a B&K ref.30 but concerned about two-channel quality. What is a good up-grade that gives me excellent two-channel as well as good multichannel performance? I am at the crossroads of audio up-grade.New formats, players, SACD vs HDCD, 5.1 channel CD's, DVD-Audio. It's very confusing. Help!