Getting a reliable pre-pro that's not expensive is going to be the trick, it would be much easier to get a receiver and build from there as you suggested. The Onkyo 708 would be one suggestion as that is where 7.1 pre-outs start for Onkyo. They give good bang for buck, but I'm sure there are other brands. On second thought, try to find a 707. It'll be much cheaper since it's being replaced by the 708, maybe 550.
I've got some Emotiva products and have been quite happy with them, so again going with the bang for buck idea, the XPA-5 would make those Focals sing, with 200 watts by 5. I've got the XPA-3, and those amps are well designed and do not run hot or even warm unless seriously cranked. So far we're talking about 750 for the amp and 550 for the receiver, 1300. Rear speakers shouldn't be a problem for Focal but I'm not sure what you mean by the Panasonic 65, a blu ray player? Not sure what the vt25 is either, excuse my ignorance!
But for not much over 2000 you should be set, happy hunting.