Which Amp? Onkyo, Emotiva, Marantz, etc.


My 15 yrs old receiver died recently & I've the opportunity to upgrade. I'm planning to use Oppo BDP-105 in Pre/Pro mode in 5.1 setup.

I'm considering the following similarly priced ($1500-$2000) used/refurbished devices:
Amplifier: Emotiva XPR-5, MARANTZ MM8077, Onkyo PA-MC5500
OR
Receiver: ONKYO TX-NR5010, Onkyo TX-NR3010,YAMAHA RX-A3020, DENON AVR-4520CI & MARANTZ SR7007.

I do understand that the separate Amp would provide better sound & upgrade path but receivers will provide better functionality & features.

Which one would you recommend? I'm open to any other devices than the ones listed above.

Thanks for your time.
hitsofmisses
For starters, could you list the size of the room, the volume level you usually prefer(what decibel level?), the speaker models used and the old receiver model just for reference. I ask this because you have a 400 wpc amp listed, and unless your room is massive and your speakers quite large you might be buying watts you'd never use.
I agree with Runnin about sizing the amp properly to the room/speakers. More info. from you will allow us to make more informed recommendations...

-RW-
Thank you guys. Here's the info requested:
Room 16x18+ with some open area, so sound can bleed
Speaker: Tyler Acoustics Linbrook System II (L, R,C)
Speaker: JBL S312 (RL, RR)
Receiver: Kenwood VR-4090B
Volume: 32
BD:Oppo 105
Tape Deck: Nakamichi RX-505

I usually watch movies but at times, like to listen to tapes.

Hope that helps!