Ok, I've just had a look at how PC Gen manages this. It's rather interesting, but I have a couple of concerns.
The first is that I'd have to manage long lists of spells (as I recall, there are over 300 spells merely in the CRB) that will encumber quite a lot the comboboxes and make the extension a bit cumbersome to use. I'm not even sure the comboboxes in Fantasy Grounds could withhold such punishment. Perhaps there are other widgets available that could handle this better, but I'd have to spend a lot of some time experimenting.
My other concern is that is that searching for a potion/wand/scroll from an item module (such as the PFRPG Magic Items module or my own Ultimate Equipment module) will probably satisfy 95% of the needs of most GM and players while being much faster than using such an extension. I'm not sure I want to spend a lot of time programming something that would save me perhaps a couple of minutes... per campaign.
I'm not rejecting the proposal outright, but I'm afraid it would be rather low on my list of priorities.