Axiom Home Page Forums General Discussion Advice from Axiom Owners Question about HT set up

I am going to buy a new surround sound system for my family room but I obviously don't know what I am doing. I have been doing some research and quite a few people like the axiom speakers but they are a little high in price for me.

After reading some reviews, here are my thoughts:

Left/Right: M22ti
Center: VP100 or VP150
Surrounds: QS4 or QS8
Sub: JBL E250p
Receiver: Pioneer VSX 915-K

I chose the JBL because of price, obviously.

Is it worth going to the QS8's and VP150?

Also, what does the Input Impedance mean, since that receiver is 8 and the speakers are either 6 or 8?

As a reference point, my current system is a Bose Lifestyle 5 (pretty old now).