As for the DSP, I should have said that I’ve been doing the DSP (mostly a small amount of parametric EQ) on the ancient (below spec) 2nd generation i7 I was using previously. However, it looks like 1.7 might have made this older-than-spec processor obsolete, because it doesn’t support OpenGL: Roon's OpenGL Requirements
(I was running server-only, but it worked.)
I’ve placed an order for a Shuttle XPC XH110 barebones system, ($180) and a 7th Gen i5-7400 processor (also $180). This system lets me keep an internal optical drive for CD ripping when I need it. I have a friend who works for Microsoft, and I can get Win10 Pro through her for $40. I can pretty much complete the system with hardware I already have, including an M.2 NVMe boot drive, which should help performance considerably. I was hoping to spend a little less than this, but all the hardware in my old machine was ancient, so I guess it was time.
Thanks for the advice! I’ll try to post an update after I get it up and running.