Of the brands sold at Best Buy, I like Yamaha best. I think most of the higher end models they sell will do 6.1, not 7.1, but the only difference is one rear center speaker vs 2.
They also carry the Pioneer 812 and a Kenwood 7070, which are about the best non-Yamahas they have. The Kenwood worth looking at has THX select certification, not a must have per se, but some assurance of real power output when looking at sub-$400ish receivers.
All have sub pre-out, and you really only need one of these. In order to run 2 subs you just need a Y cable with male RCA jacks to split the sub output. These are easily available at BB or Radio Shack.
At Bestbuy I would have to agree that Yamaha is your best choice. Unfortunatly you won't get 7.1, only 6.1.
The two next best would probably be Pioneer and Kenwood. Also, Bestbuy seems to offer some Panasonic recievers and that is something I would probably stay away from. Nothing but trouble with mine.
if its because you need it to be a local chain store for ease of purchase and warranty you might want to see if you have a compusa in your area, because the ones near me sell harman kardon recievers which do 7.1. in fact i think circuit city does as well, which also has onkyo.
if its because you get a discount as an employee or have a gift card then the previous two posts had solid advice.