I think an interesting 7 channel (or 5 channel) project for a second HT system would use 4 x $20 T-Amps (8 channels) and a dedicated processor. A nice Sony TA E9000ES 5 channel processor (SUPERB sound quality!) can be had for $300-500 on ebay with 3 T-Amps and some power supplies and some M22s or M3s/VP100/150s up front would be superb - I think (haven't tried it myself)
Another thought, if you have a 2 channel amp or a 3 channel, seems to me that the T Amp would be perfect for the side/back surround channels.
