In shStudio under Light Gears or Dark Gears, when you select "Create Item", you can choose:
Type 66 - Helmet
Type 67 - Armor
Type 68 - Pants
Type 70 - Gauntlet
Type 71 - Boots
For Light Gears
Type 81 - Cap
Type 82 - Protector
Type 83 - Leggings
Type 85 - Muffler
Type 86 - Walker
For Dark Gears
Same goes for weapons.
Instead of creating new items, I would suggest using the empty slots first. Go to All Items, then scroll to the item type you want (for example Bow, Spear, Dagger etc.) and edit one of the ???xxx (where xxx is the item number) to your liking. You can change the name, stats, appearance, classes, faction, mode, element, speed etc.