How loud are you listening? Do you have a db meter to give you a rough idea? You might be surprised and how little power speakers need in order to be driven to relatively high levels.
Try this calculator... it seems to be a good approximation. I'm guessing the Aerial 6's are 86 db for efficiency and probably 4 ohms (the new 6T's are on Aerial's website now, so the old stats are gone).
You'll probably end up with something in the 95-105 db range.
Also, what's the power to your equipment?
I just have my stuff in the living room (no dedicated HT room) without a dedicated power line. I was kidna blown away when i did some math.
120v * 15 amps = 1800 watts, max. Really, my power dips down to as low as 115V sometimes, and I'd bet the breaker trips a bit before 15 amps.
In my case, my plasma TV can take up to 450 watts (most 50-60" LCDs seem to use around 200-250 watts), and I allotted 75 watts for my bluray player, 75 watts for my processor, and 100 watts for my sub woofer so that's 700 watts total. That leaves 1100 watts for the amp. And that's maximum, assuming NOTHING else (lights, ceiling fan, etc) are being used on that particular circuit.
Amps seem to have an idle (no signal) power rating. In my case, 200 watts. After that, (on a class a/b amp), you probably get about 1/2 of the used power going to the speakers (due to efficiency). In my case, 900 watts 1/2 of which is only 450 watts total.
I'm going to make a guesstimate and say 120 watts to the front three, 45 watts to the back two. It'll really depend on what you're listening to and how its mixed.
Without a dedicated line, you aren't really capable of pulling a whole lot of power. And, I'm not sure that "more" continuous power = better sound. More capacitance (stored power) for instant power needs is probably helpful.