I'm liking this idea a lot for some major game variance, and had recently started working on a mod I was going to release in tandem with mine called "Improved Combat Encounters" that added items from my mod to the encounter lists, add new enemy types (with player abilities like Heal, Disabling Strike, Sedation, or even Shackle to prevent player escapes), and then add those as higher combat difficulty options for the "deeper regions".
I'd be happy to combine this somehow with your endevour, but the catch may be requirements. I'd hate to force people who didn't want to use my Expansion mod to skip this one because items would be in the list.
What I may suggest, if you're interested, is combining our efforts to add the additional enemy types and encounters and simply have 2 mods released, 1 with updated item lists for compatibility and 1 without?