The only item in that price range $1,800 that is of slight interest to me is the Marantz Av8003. Here is the link
http://us.marantz.com/Products/2317.asp
I have not listened to the unit and tend to shy away from receiver makers. But this unit gives you all thru HDMI with room correction which may be of interest to you. The unit has some good reviews. The other alternative is to use the analog 5.1 or 7.1 outs of your Oppo to an older pre pro. That will depend on the quality fo your Oppo analog outs which I kinow nothing about since I have a Pioneer unit that was touted for their analog outs. Your Oppo must have many controls for the analog outs (delays, crossovers etc.) for this kind of set up since most quality manufacturers of prepro just pass the singal thru. You would directly connect the Hdmi video from your Oppo to your Elite which is my preference anyway. Have been looking at Classe' 300 and 600 along with Bel Canto but they are $2,300 to $3,00 used and Not in my current budget. I'm stuck in no man's land.
Good luck