I prioritize m.acc to the point where you stop getting resists against your target (I use 480 base m.acc vs. Garuda, ~450-460 against everything else), then it's a toss-up between INT and m.atk depending on what you're doing. If Thundara is the bulk of your damage, then INT is slightly better, but for everything else, m.atk is better point-for-point.