+1 for Paradigm. I love mine.
I agree on the Atoms being a little light for the midrange, but have a listen to them, they may surprise you. I originally intended to go with Atoms all the way around but after auditioning them I decided to to fill in the midrange a bit (as Jesse suggested above) by going with the Titans, which have a larger driver. For their size the Titans are pretty impressive and that's a great center channel. I also considered dipoles for the rear, but my living room at both places has been a little small to warrant those and made mounting a little tricky.
My setup is 4 Paradigm Titans, Paradigm CC-270 Center? (Edit, I had to go check the model) and Martin Logan Abyss Sub. I'm powering it all by a lowly Onkyo receiver and I love it. Someday I may ante up the cash for a proper amp, but so far I've seen no reason to upgrade.