Good Processor

You need to determine if the old receiver digitizes the 5.1 analog and apply room correction, bass management etc. The Oppo can do the bass management, but I do not think it does the room correction. Most receivers do not do room correction on the analog inputs. Because the Meridian is all digital, maybe it does. Also, does the Meridian have 5.1 or 7.1 RCAs or does it use a proprietary connection?

Meridian also has, at least to me, a characteristic sound that is much more digital than analog. You need to decide if you like that sound or not, especially for 2 channel music.

1. Few (but some) old receivers will redigitize the 5.1 analog but that is not optimum. If you want it to process digital (RC, Bass management, etc.), feed it digital
2. Oppos do not do room correction.
3. Meridian does RC below 300Hz which is where you really need it.
4. It is not standard but the Meridian 861s can be configured with a 5.1 RCA analog input.
5. IMHO, the Meridian sound is surprisingly analog and liquid.

I'm thinking the integra 80.3 is the way to go for me. Suggestions for 5 channel amp? Will be driving Merlin TSM for L,C,R and sonance in ceiling for surrounds.

If stereo is very important, going with an AVP can be very limiting in terms of viable options as you well know. And it may also be more expensive relative to using a quality stereo pre for the front L/R speakers and a decent AVP for surround processing and channels. Then again if surround processing and quality of those signals are just as important as stereo (or you're space constrained) I guess it could be worth the additional expense and limited choices for a good AVP. Just in case you hadn't considered the possibility of using a stereo pre in your setup. Best of luck.

I am totally pleased with my NAD T175HD pre/pro for HT, multichannel music, and 2-channel music. It really does do all three very well, IMO.

Bill