I have the Denon AVR-X3400-H and love it I use it as a pre/pro thru my Outlaw 7700 amp.Personally I would buy an AVR and use that as a pre pro. Some of the Denon and Marantz are able to shut off the interior amps when you use your external lamps
I like the Denon 3600 you can still find them on Amazon for $899 new. They don't shut the internal amps off but they have Pre/Outs and the Denon 3600 tested really great on the bench test
Not sure what the comparable current model is Had it for 18 months and no problems.