The Onkyo TX-SR876 is only $849 right now at Accessories4less.
Great receiver, best value there is. I know, I own it.
* As for an amp, the Emotiva XPA-5 is also excellent and of great value.
But, with the Onkyo TX-SR876, I don't think you'll need it, cause the Onkyo is THX Ultra2 Plus certified, and is rated to drive 4-ohm loads. And it's plenty for your room's size. And you also have a sub, so you'll be using a x-over in your receiver; tha'll give you extra headroom.
-> By the way, your Yammy 2600 is a great receiver, with a fantastic preamp section, a small gem, not known by too many people. So, you can still use it, and just add the Emotiva XPA-5. Another nice option.