I would avoid Onkyo, they have been having problems with boards over heating. No receiver is full proof, but Denon, Yamaha, Pioneer and Marantz seem to have the better track records.
Yamaha RX-V571 is $400, including shipping.
That leaves $600 for a couple towers.
Infinity Primus seems to be popular on here, but I like these;
ERM 6.3.
They have awesome customer service, free shipping, 5 year warranty, and IMHO, I think they are a better built speaker than any other speaker in this price range. 3 of those would be perfect match for LCR setup, too.