Personally, I would always rather go with a full range speaker than to try to pair up my speakers with a sub-woofer, so if you feel you need a sub-woofer with the N803's, but not with the N802's, for me that factor alone would decide the issue in favor of the N802's. You may still want a sub-woofer for home theatre, but that's another story. To my ears, if the N803's are given proper amplification, they do not need a sub-woofer,
but if you have the budget and the room, the N802's are a significant step up -- and it is your ears that matter, not mine. But, the next problem I see coming down the pike is that I don't believe your CAV 180 amp is going to do justice to either the N803's OR especially the N802's. You are going to need some serious amplification to make those babies sing. If you are going to go with the N802's, which I think is a good idea, I would seriously consider a stereo or monoblock amps for your front two speakers. Use the CAV 180 to power the rest of your home theatre speakers. If you like the Classe sound, you might look at the CAM 350 amplifiers. Those would power your N802's nicely.