[ericthered]

Banestorm has mystics. These are rare even compared to mages, and while their existence doesn't prove anything theologically, they work as though their faith was true. Wizardry should probably not use divine favor, but these folks are a near-perfect fit.

RPM can work and fit well if you're willing to tweak it enough. My tweaks where to cap magery at a low number, forbid ritual adept, require spells to be known (you can't make it up, but it costs no points to have access to a ritual), and to strongly encourage using the Specialization Traits from pyramid 66. Its not a perfect fit, but it was good and different. Also, path of Gate isn't taught, because you've got to overcome this massively overgrown botched spell that covers the planet,

Imbuments I would categorize as at best an incomplete fit: They aren't scholarly, aren't comprehensive, and fit a particular type of action. I could see a couple of imbument wielders floating around, but not many.

Threshold magic actually is a pretty good fit. big exertions by mages rather than small ones works well in banestorm.

Ritual Magic also works well, possibly alongside the standard system.

Realm magic also fits, though in this case it looks fairly close to the standard system.

Sorcery I would not recommend, but that's because sorcery has left a bad taste in my mouth. I strongly prefer magic as powers. The difference in game play between the two is strong, but building the actual "spells" is pretty similar. Magic as powers is a decent fit, but not particularly strong compared to some of the other options.