My favorite mod is Undead Legacy. It lets you craft schematics for the items you need by scrapping the ones you don't need. You can find cars in the world and repair them to full working order, including lights and sirens on police cars. The progression is much more granular with item tiers doing from H all the way up to S three stars, and that includes the item mods now. Your inventory is weight-based instead of slot-based (except for containers) and you can carry a much wider variety of gear.

If this mod sounds fun, I strongly recommend also adding the anti-bullshit sub-mod that someone made for UL.