Ah! It doesn’t have to be squat!
My favorite little computer for that kinda stuff is a Lenovo Tiny 340.
We chatted a bit about options here…
Any of those models should work. The Lenovo I think it might have been @ALan 's recommendation. The Windows experience, and, if you are REALLY up for it, maybe get Mr Susanne to hook you up with a dual boot Windows and Ubuntu. Ubuntu and Windows mean pen pressure sensitivity with RGS and far easier USB Bridge mode for Teragucci. Using a laptop will require an external screen of course, which Im sure you have. Just be mindful of resolution for that. 1920x1200 is safest, but some go for whatever the next size up is. 2500x1800 something ish?