Stay W/B&W 805's or goto a bigger speaker

Please help with any feedback. I have a Proceed PRE & a Classe' Ca100 amp. My CD player is Ultech UCD-100 and I have a Velodyne fsr-12 sub. I'm trying right now it without the sub in place. I'm not really sure what is the best way to hook it up.Also instead of buying extra cables to hook up the sub, would it be better to just buy bigger speakers? Also I would like to buy bal. cables to the amp, but if I hook up the sub inbetween the amp and pre I would have to go unbal.
Thanks for any answers, Jim