Time to upgrade Mac mini 2014

Just to clarify, I can be a bit slow at times :)

I’m using the Mini HDMI out to the Oppo for its DACs, then feeding the Pre-pro. The WiiM is listed as Roon ready, which the Oppo is as well, so it is not a server, correct? 
mid I use the WiiM, then I have streaming, but not a Roon server

a new Mac Mini (599) is the direct replacement and gets me back to what I had

Sonic Transporter is a direct alternative to the Mac Mini, a server for Roon and with added storage will store my small library (1295 new with onboard storage)

Do I have that right?

I’m not opposed to the cost difference of the ST over the Mini M4, but I don’t want to get into the Innuos-level gear (yet)

Don’t think that you are slow it’s just if you just get a dedicated streamer and if you wanna start out cheap get a WIIM player. That’s it there is nothing more you need. There is no need for roon Even though that is what you know. I think once you understand, which you only can once you have it in your hands experiencing the user experience seems to be a mystery until you have experienced it. So go on Amazon and get this puppy or one of its lesser brothers and then come back to the conversation and ask the questions you need to ask.https://www.amazon.com/WiiM-Streamer-Touchscreen-Compatible-Headphone/dp/B0D41YCLW8/ref=mp_s_a_1_1_sspa?adgrpid=83416784050&dib=eyJ2IjoiMSJ9.DYu9-dfKarsSQT2l_ABvNrXo2JNxZB2wIvy84y3XSqoKoQhJ2oC-A5920AH8kKM9Ellr4RhE1uch1wmQh5DnMRKwKxO-x_ODF-3yBbH5xjS9D9zF0fsX1tautLMjJxoU8rcsruu9ZOfFZjQBKTUUJEcrRMnYT2jTuCtsGx4n7aPGBT554tgbi-npAx_14pJFSZiM7P6v-FfLzHGCgql2Mg.rAuDyCz7OBWMryPpWKYjaU4MiG3Nhwz1yEsxIZtap0g&dib_tag=se&hvadid=776650889682&hvdev=m&hvexpln=0&hvlocphy=9033780&hvnetw=g&hvocijid=9864162695412953612--&hvqmt=e&hvrand=9864162695412953612&hvtargid=kwd-2241064493880&hydadcr=20578_13636955&keywords=wiim+ultra&mcid=f5f92c02685332a185d2403f93e577fc&qid=1762181387&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfYXRm&psc=1

Enjoy the sound!

We used a old macbook as a music server then went to a Wiim Ultra as it has the ability to connect a usb drive for music.  Love it, great software, easy to use.  we go out to a MHDT DAC.

i have a new mac mini i use for my photo work, damn they are fast.

I’m using the Mini HDMI out to the Oppo for its DACs, then feeding the Pre-pro. The WiiM is listed as Roon ready, which the Oppo is as well, so it is not a server, correct? 
mid I use the WiiM, then I have streaming, but not a Roon server

a new Mac Mini (599) is the direct replacement and gets me back to what I had

Sonic Transporter is a direct alternative to the Mac Mini, a server for Roon and with added storage will store my small library (1295 new with onboard storage)

Do I have that right?

yes 

I'd actually recommend you keep the Mini if aftermarket support for minis dedicated for streaming was still there. I used a series of modified dedicated mini streamers over the years, definitely superior to mid tier and lower off the shelf streamers. I'd suggest the Wiim more lateral move than upgrade from the stock mini you have.