Bluray Hi Rez audio

I am not quite sure what you want: hdmi into usb? The Oppo UDP 203 has both optical/coaxial digital and hdmi audio output. Since you are using the digital outputs bypassing the internal DAC there is no need for the more expensive UDP 205 with its superior DAC.

Your current Oppo alrerady has optical and coaxial digital outputs, I am almost sure up to 24/96, and it does DSD according to the manual. The main justification for moving up to the Oppo 205 would be to have 4K video (if there is any source material that you are interested in - there is very litle right now). And of course you could use it to reduce the number of boxes: it can serve as a fine disc player, an excellent DAC and a perfect pre amplifier, all in one box.