With my Oppo I can now do 7.1. I currently have 4 DSP5000s and a DSP5000C.

So ... another pair of DSP5000s or get some DSP3100s?

If DSP3100s, would you make them the surround pair, or the rear pair, in a 7.1 system?

Cave: Trinnov Altitude CI-8; Oppo 203 Vanity HD; 6xDSP5k, DSP5kC, D1500; Sony Z9D, PS5 Pro; Apple TV 4K
Living: Wiim Pro; Rega Planar 1+; 2xDSP5k
Master: Wiim Pro; 2xDSP3100
Kitchen: Bluesound Flex stereo pair / Amazon Echo Studio
Deck: Wiim Mini; Random Chinese Class D; Cambridge Soundworks Outdoor 52s; Polk Sub;
Garage: Wiim Pro; 2x5k