Hmm, let me see. Well, it's mostly one hero that can be built differently so there should be the following slots:
Weapon - Item that could fit here are swords, bows, axes, staffs and possibly spears; Armor - 3 types of armor - Heavy (plate mail), Medium (chain mail) and Light (leather).
2x Trinket Slots - Items that go here are rings, voodoo dolls, luck charms etc.
Necklace - pretty self-explanatory;
Secondary Weapon - things such as shields, specialized quivers(add [ranged] attack effects?), Swords, Axes (for offensive two-handed play).
Magic Gem - Each Gem gives the player 2 abilities related to it's element (fire, ice, nature) - 6 gems in total. These can be upgraded via magic merchant if possible? - if not, just make the spells scale based on stats and etc.
Leggings - These have more of an impact on your movement speed in certain regions and the amount of energy lost while moving in those regions (Energy will replace wood and have a general amount of ~1000 which drains slowly and can be restored by going near campfires or markets) = E.g. - Leather ones are great in snowy mountain terrains but not in rugged lands. Chain mail ones are great for rugged land but double the energy lost in the moory areas and the dead lands. There could also be Reinforced leggings but those while good for most terrain cripple the movements speed. You get the idea.
Helmet - Basic Armor item slot, nothing too special. Has an impact mostly on vision radius.
Feel free to download any attachment models you approve as well as the multi-animated villager. As for example Items, I gave some types of items which, i guess you could start with the most basic versions, the "tier 0" and expand on those later on. As for the attachments, i think most practical would be to use them only for weapon 1, weapon 2, armor and helmet slots as the others would look weird, but I could be mistaking.