That's going to be close. Historically, as receivers go(considering driving internal amps), Denon's have been more warm/full bodied, with slightly less extension, while Yam's have been more "coolish" sounding, if hollow in the midrange a bit, and a bit bright overall. AS pre/pro's from their pre-out's into another amp, that you might have to just try! I would start with the less expensive V1400(Actually, I'm familiar with RXV1400) and try that from it's pre-out's! The Yamah's probably are Ok if you just run from a digital connection. I think you could sell otherwise.
My suggestion however, is to forget all of the above and buy a superior (with more features for audiophile grade sonics) Outlaw 950 pre/pro and be done with it!...forget the receivers!
Receivers are notorious for being less dynamic with higher noise floors from their pre-out's! Better separates pre/pro's usually offer better channel separation, better dynamics, better signal to noise ratio (i.e, quieter), and better refinement often(depending of course). Still, if you could pick up say a $500-700 receiver for say $300, it might be worth a try. Otherwise, the Outlaw is going to be superior for dirt cheep. Good luck!
