Dear,
Yes wires play role..
whatever receiver you choose....choose Subwoofer & center speaker carefully.rest of the speaker you wont find any difference in same price range..
the difference you could identify(in hearing) in expensive HTs and cheap Hts in Subwoofer and center speaker..so do mix and match for sub and center..and AVR doesn't matter..No one could Identify the difference id same speakers are used for the different AVrs in same price range..
For music you need 2 channel that means two front speakers should be good..you can go for book shelf..since you already has subewoofer you dont need floorstanders..
cheers