Hi regular-wine,

There is Cinebench as an orientation of what you might get from one or the other. Google about score lists.
https://www.maxon.net/en/downloads/cinebench-2024-downloads
https://www.maxon.net/en/tech-info-cinebench

I typically do not suggest hardware here, as that is quite difficult. But besides the cost, the Mini or the Studio seems to be quite different to me.

The models you mentioned are currently kind of mid-cycle. At the same time, the M5 seems to point to a new level of speed for all, just guessing.
https://buyersguide.macrumors.com/#mac

My main tip would be to invest in screens that can perform HDR values. For a long time now, that is a critical production point, besides larger Gamuts.

If your MO is to squeeze a long-running time out of the hardware, make sure it stays relevant for a long time, stating the obvious, sorry about that, which means more of an M4 than an M3, and typically more power, etc.

That is already more than I'm comfortable sharing.

My best wishes

P.S.: …how about iMac24" and an extra Screen?