Couple of thoughts:

First, welcome to the forum.

I have always (since 1983) built my own computers until the most recent one, and always used Intel chips. This dates to well before there were some small incompatibilities between software and the AMD chips. Those incompatibilities appear to be long past.

To choose a CPU between an i7 and an i9 depends on the rest of the specs, since some i7s (and even i5s) can be faster than the slower i9s.

When comparing equal speed CPUs, go for the one with more memory cache. Then look for more cores.

For BIAB only, graphics (either integrated in the CPU or an add-on card) does not matter at all. In general, except for graphics, you are on the right track to consider a gaming rig for digital audio. Since I don't do gaming and don't need good graphics, I like the Intel chips with integrated graphics. Graphics cards these days are very expensive and are generally noisy, which I can't stand in a digital audio rig.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.