and should i go with the 4 channel or two channel?
Depends if you want to buy one amp or two...
Seriously though, Whats the point of running the amps off the preouts you have on your receiver now, you're not putting all the speakers in the same room as your setup now are you?
Lets be practical... Buy a cheap stereo receiver with A+B outputs so you have an entirely different system not dependent on the other one. YOu dont need gobs of power and those amps have mixed reviews.
Sell one pair to somebody you dont care about and use that money to buy a cheap receiver to power the other two...
