Stat caps for items throw a monkey wrench into that plan. Especially since HQ items are typically at their cap for the stats on them already. That said, putting enough perception materia in your gear to hit the cap on all of them would, of course, result in the best perception you can have.

As this is based on item level, I wonder if it might be a good idea to, rather than use gathering accessories, use the level 70 tank/dps/caster accessories instead, as they may likely have a higher stat cap.