I've never been one for the use of a receiver. Separates all the way! I'm not one to want all my components to be matching from the same manufacturer either (I can't believe that so many people are concerned about that). A great system includes components from many different manufactures.
What is needed is a good surround preamplifier, one that includes multiple analog inputs. That's why I like to custom build much of my equipment, you can't always find something to suit your needs commercially. Any suggestions for a great multi-channel pre-amp are welcome here, sorry I haven't any suggestions myself.
Anyway when it comes to amplifiers I would suggest looking at professional units. I own a Crown CTS 4200 four channel amplifier. As well as a CTS 8200 eight channel amplifier. Both were obtained used at a very reasonable cost. They are robust, sound good and have balanced inputs (but you can run still run them single ended). The CTS 8200 that I have came from some commercial use and thus has a digital add on board to enable control via Ethernet, as I don't know how to remove it I just have to let the amp boot up twice, the first time it sees no control signal and so then reboots, defaulting to the analog inputs. I consider that a small price to pay for a great amp at a great price, I'm bi-amping quad with the 8200 but it would be just as useful for 7.1 surround or 5.1 surround possibly with the front channels bridged for higher power.