Currently have the B & W 686 with chord carnival silver screen which is not quite long enough (long story), hooked up to denon 2310. I have my fronts 684's Bi amped at the moment but in the future will be plugged into to a seperate power amp. This will mean more channels free in the denon. I have not come across any modes which suggest I can but would I be able to bi amp the rears once these channels are free. Is this only possible with another amp? I ask because when I order silversreen bi wire I need two lenghts of ten metres which is going to be about 250 pounds and want to know whether I should wait and purchase a 4 to 4 combination of bananna plugs when I have the channels or if it wont be possible just get the a 2 to 4 and bi wire it now. Hope this makes sense.