Going Tidal, Need ???

I don’t think you need any new hardware. I also have an Oppo 205 and it works really well with Roon and Tidal (inc Tidal’s lossless and MQA content). Someone mentioned jitter, the Oppo 205 supposedly has some additional features to help manage that (link below) although I actually use the XLR analog audio out from the 205. Either way if you have a UDP-205 I think you have all you need for an excellent Roon/Tidal setup.

https://www.oppodigital.com/KnowledgeBase.aspx?KBID=129&ProdID=UDP-205

adding one point - the UDP-205 does indeed support MQA. Tidal has quite a lot of MQA content now (in addition to the lossless FLAC you get on the Tidal HiFi tier). You may need to use the USB DAC input for MQA.

Firstnot, honestly I'd just give the 205 a try.  You have it already and it really is all you need to get started.  Get a free trial of Roon (you can find 14 day/30 day free trial codes if you look around). You can then use an existing Mac or PC as your Roon Core (if you have an iTunes library etc on that PC then Roon will tap into that).   Provided your PC (Roon Core) and your UDP-205 are on the same network it will show up as a Roon endpoint and you can use your PC or the Roon app on your phone or a tablet to control your music.     You can buy standalone Roon Cores, Roon Nucleus, and store music on that but you can use what you have for now and see if you like it.  If you have a PC, a 205 and a Tidal account it won't cost you a penny to try it and I am betting you will be as happy with it as other Roon users are.   

Good luck and report back.  Interested to learn what you think!