No specific models as such, as I'm still a desktop person
Zbrush's specs are listed
here and they're reasonably modest.
You shouldn't be doing much of anything with textures, so that will help. Keeping poly counts low helps as well (although zbrush is remarkably good at handling dense models). How dense you make your meshes is up to you, but there's no point creating detail that 3d printers can't print.
A graphics tablet is pretty much essential and zbrush now, finally, supports the spacemouse (although it's very much optional, just cool and fun to use)
Zbrush does run quite happily on my Surface Pro 3 running windows 10, with an i5 processor and 8GB ram, so you shouldn't need to sell a kidney for it (buying zbrush, on the other hand, may require giving up a bodily organ of choice).
The one thing I would say is to make sure that whatever machine you buy is capable of running Windows 11 when it comes out. It has some requirements that are beyond a lot of pretty modern kit out there.