Features:

• Works out of the box with every possible weapon with "spawned_weapon" class, so basicly every weapon dropped via /dropweapon on darkRP
• Very powerfull and advanced config
• Entity based config - you don't have to make whole array in the script to declare every pickable item like in other inventory addons, you just add from 1 to 3 lines in shared.lua of entity
• Storage system
• Vip / other ranks integration - You can change max weight of inventory and bank for every rank (default there are settings for "user" and "vip", if "vip" doesnt exists it uses "user" settings, if user doesnt exists.. well.. It's gonna use default static value.
• Many of visual effects like holo and sounds ready to configure
• Simple and intuitive drag&drop
• Customizable colors - you can set up 2 colors in config, and it does change every vgui and 2d3d gui of this script.
• Less than 200 KB size (both client and server scripts)
• 3 Example entities. (2 are just useless, but different weight for test purposes, and one is medic kit which actually works.)
• Well support - if you're having any problems I'll help or/and refund.

The config:

InventoryConfig = { 
    General = {
        playerDataFolder = "inv_data",
        haloEnabled = true, -- This is the holo around pickable items rendered when you aim at these items
        haloColor = Color(255,255,255),
        keyBind = KEY_F3,
    },
    Colors = {
        primaryColor = Color(42,43.5,44.7), -- darker
        secondaryColor = Color(60,60,60), -- lighter
        textColor = Color(255,255,255), 
    },
    Sounds = {
        pickUp = "physics/cardboard/cardboard_box_break3.wav", -- Plays when youre picking up object
        dragItem = "common/talk.wav", -- Plays when you're dragging items in inventory / bank
        openStorage = "ui/buttonclick.wav",
    },
    Groups = {
        user = { 
            inventoryMaxWeight = 25, 
            bankMaxWeight = 250,
        },
        vip = { 
            inventoryMaxWeight = 45, 
            bankMaxWeight = 450,
        } 
    },
    Messages = {
        noSpace = "There's no space in your inventory",
        tooHeavy = "This item is too heavy",
    },
    GuiText = {
        use = "Use",
        drop = "Drop",
        dropAll = "Drop All",
        totalWeight = "Total weight: ",
    },
}