I have 3 fighting classes at 50(+scholar) and 3 doh/dol classes and Im having lots of issues finding space for all the gear. My armoury chest is 25/25 in every slot. And my inventory is 2/5 gear (sure most of them are vanity items but Id rather have them there than on my retainer if I realize ina dungeon that my shoes dont really fit my outfit). But I reckon if you dont collect vanity its easier.

It will take ages though! Currently working on my BLM and it has been between level 30-35 last two weeks doing one dungeon every other day.