How much would be lost if........

I am thinking of integrating my HT and my stereo, I mean just using stereo speakers up front(NO center channel) and a set of surround speakers. I have a good sub also. I realize I will never be able to fully experience 5.1, dts, etc but is pro logic that bad? can I have seperate L and R surrounds with this set up or is it one signal that will be sent to them? My speakers are very holographic and tend to create a center channel when listening to music, also the company who makes them does not make a center(I use avalon acoustic eclipse just for the record). My other option would be to seperate the two systems and use much cheaper speakers in the HT. So I guess my question is: do I really need a center channel to have a good HT set up? any further questions/coments are welcome. Thank you for any help, Tim.