There is currently no item that provides Gildar continually, or any other resource. How about the Golden Belt provides 5 Gildar + 1 Gildar per level (or something similar for balance).
Also, what about the Enchanted Backpack providing a random resource boost per turn? (This could be in the form of base amount + amount per level, balanced for each resource too.) It could be Gildar, Metal or Crystal (or even Mana), or if you're keen, maybe you could drag Horses and Wargs out of it occasionally (although you wouldn't be able to use them until you got the techs).
Both of these items would provide the resource boost at the start of the turn, so you would need to have them equipped when you click Turn.
What do you think? We currently have no income or resource boosters as hero items, so why not change this? Certainly more interesting than +1 Initiative and more appropriate than 25% Splash Damage.