I uhm. Okay. So this isn't really an item suggestion, I don't think? But rather a UI recommendation, but I have no idea where else to put it. It'd be nice if you could make it so that items auto-sort next to each other in the avatar and marketplace without me having to go into my inventory and move them around? However. My alternative idea is to make items in the avatar dress up thing stack and only separate upon one being selected for a purpose. Oh I have 4 of this item, and when I put one on it changes it off that stack and to the selected form like normal, and now I have 3 of this item in the unused stack and next to it is the one of it's selected forms. I don't really know how you might do this, but currently the avatar dress up thing is incredibly inconvenient to use. I find myself having to go into my inventory to sort stuff around for ages, and that's not fun. It's tedious and frustrating. Additionally, you could add an ability to sort your inventory that isn't manual based on the primary features of said items. Like, sort by item type "Hats, tops, bottoms, etc."
Anyway, I dunno if you have a better place for this or not, if so.. Well, link me and I'll post it there. If you're already planning something, that'd be good to know about. But right now I hate dealing with my inventory, probably the thing I enjoy least on here at the moment.