TV,
I hope I don't appear snooty but Mackie and Samson equipment is generally considered KMART type stuff compared to Crown, QSC, Crest etc. Maybe I'm off base but I would think some people might get the wrong idea about SVS when they see some of the brands you pair up with the speakers (like that $179 eq).
I think the Crown way would be good and by HT standards the amps are fairly cheap (especially considering power output).
One last question of you, I want to go with the new Lexicon MC12 processor and it has 3 sub outputs Left, Right, and Low Effects. Would I be losing anything going with the 4 Ultra setup (2 Left, 2 Right) and not using Low Effects output? This would save the money for another amp and subs.