Which CPU or Get New Mobo and Ram?

Ok straight up I am thinking about this too damn much and I just need help deciding shit now. I have a few choices in front of me and I am a bit baffled about what to do. A while ago I thought I broke my 3900X when I dropped it and broke a pin. Turns out its fine, however before I learned that someone sent me a board and a chip and now I have a P9x79LE with an E5 1620 in it clocked at 4.7GHZ. though the system claims 5.3. Whatever.

Switchable to this 1620, I have a 2690V2 that, while I can’t really overclock, DOES have 6 more cores and 12 more threads.

So why am I thinking about this at all?

My upcoming things I see myself doing:
Music production
Console hacking
Linux Package Production and Repo Management
General Office work and Gaming BS (Literally Fable, Fortnite, Tarkov, and maybe like minecraft)
Temporary Server Hosting
VMs

I happen to not have any money as well, and a 3900X is still worth something. I am thinking sell the 3900X, keep the 2690V2 in my machine, save the 1620 for later if I upgrade to a chinese X99 board and sell the 1620 and the X79 board I have now, and if I’m on arm by then cool whatever idk.

My only question left is I have an R620 with one 2690V2 in it… Can I put my 1620 in there old opteron style?