Thanks for the replies!
Seanondemand - Ubiquity does look like it'd be a great solution, we have a larger back yard and an RV in the driveway that currently have spotty coverage so a modular system would be very helpful. I'm not very experienced with networking but am fluent in google-fu. I do have one more question regarding it. Just to make sure I'm not missing anything on the product description; the Dream Machine does not work as a modem, correct? If not, I still use Comcasts modem, would there be any real benefit from getting a 3rd party modem?
Brian Blankenship - I have about 4 channels all to myself with only 3 signals showing (our wifi, our guest wifi, and a printer). The extender works on a back channel, 2ghz I believe. That kinda leads to a separate issue which is that our house was pre-fab, all of our walls are pretty much solid throughout making 5ghz next to useless unless you're in the same room. I guess the more I talk about it the more having wire access points where needed seems to make more sense.
I'm thinking, the Dream Machine with 2 of the Pro AP's. Do you guys think that would cover approximately 3400sq/ft with backyard and RV in front?