I've actually already added filters for item level ranges to the drop down menus in Advanced Filters. I just have to wait to publish until 1.3 goes live as I'm using some of the new item link functions to get information.
I actually stumbled across this thread while I was looking for some tips on sorting the inventory by item quality. I'll probably pm you when I get home from work, merlight, as you're taking much of the same approach I was before I tried using libsort
