The best working solution is a HD621 HDMI switcher connected to your HDMI sources (Be they Oppo 9x or HDI streamers). The 4xSPDIF modding is a hassle and will need to be redone on all multichannel sources, -pain.

Ofcourse you would pick a 861v4 before a 568.2mm. The 568.2mm does not have room correction. Since you are doing analog the 861v4 is superior to the 568.2mm in this department as well. Also the 861v4 can have XLR outputs (check the cards before deciding).

What speakers and amplifiers are you planning on running?

DSP8000SE, DSP7200SEHC, DSP5200SE sides, DSP7200SE rears, 861v8, 210, Sim2 Ultranero 4, Stewart Cinecurve 2.35:1, XEIT CM-5E Anamorphic lens, Dune HD Duo Cinema 8K and Wireworld Platinum 48G HDMI -> UHD722 -> Shunyata Omega Ethernet. Shunyata/Furutech power-cables/filters. SR Master Fuse@861v8. Uptone Etherregen with 10MHz OCXO clock.