Which URL/Menu structure is more SEO friendly?

[MagePsycho]

I am planning to structure my menu and following 4 types came into my mind.

**Menu 1**

    Extensions (/extensions)
        |-- Magento Extensions (/extensions/magento)
        |-- Prestashop Extensions (/extensions/prestashop)
        |-- WooCommerce Extensions (/extensions/woocommerce)
    Themes (/themes)
        |-- Magento Themes (/themes/magento)
        |-- Prestashop Themes (/extensions/prestashop)
        |-- WooCommerce Themes (/extensions/woocommerce)
    Free Stuff (/free-stuff)

     

- Looks cleaner to me & require less space to fit in menu.
- More Sub-Categories/Types can be added easily under `Extensions` & `Themes`
- `Free Stuff` generalizes all the Free stuff from  `Extensions` & `Themes`

**Menu 2**

    Extensions (/extensions)
            |-- Magento Extensions (/extensions/magento-extensions)
            |-- Prestashop Extensions (/extensions/prestashop-extensions)
            |-- WooCommerce Extensions (/extensions/woocommerce-extensions)
        Themes (/themes)
            |-- Magento Themes (/themes/magento-themes)
            |-- Prestashop Themes (/extensions/prestashop-themes)
            |-- WooCommerce Themes (/extensions/woocommerce-themes)
        Free Stuff (/free-stuff)

- This menu is exactly same as #1. It only differs in url structure - prefix has been added to sub-menu.

**Menu 3**

    Magento (/magento)
        |-- Free Stuff (/magento/free-stuff)
        |-- Premium Extensions (/magento/premium-extensions)
        |-- Premium Themes (/magento/premium-themes)
    Prestashop (/prestashop)
        |-- Free Stuff (/prestashop/free-stuff)
        |-- Premium Extensions (/prestashop/premium-extensions)   
        |-- Premium Themes (/prestashop/premium-themes)
    WooCommerce (/woocommerce)
        |-- Free Stuff (/woocommerce/free-stuff)
        |-- Premium Extensions (/woocommerce/premium-extensions)
        |-- Premium Themes (/woocommerce/premium-themes)

- Require more space in menu.
- If you want to add New Type(Drupal, Joomla etc.), you have to be careful with the available space in menu.
   
**Menu 4**

    Magento (/magento)
        |-- Free Stuff (/magento/magento-free-stuff)
        |-- Premium Extensions (/magento/magento-premium-extensions)
        |-- Premium Themes (/magento/magento-premium-themes)
    Prestashop (/prestashop)
        |-- Free Stuff (/prestashop/prestashop-free-stuff)
        |-- Premium Extensions (/prestashop/prestashop-premium-extensions)   
        |-- Premium Themes (/prestashop/prestashop-premium-themes)   
    WooCommerce (/woocommerce)
        |-- Free Stuff (/woocommerce/woocommerce-free-stuff)
        |-- Premium Extensions (/woocommerce/woocommerce-premium-extensions)
        |-- Premium Themes (/woocommerce/woocommerce-premium-themes)

- This menu is exactly same as #3. It only differs in url structure - prefix has been added to sub-menu

Moreover, I am targeting for following keywords:

- "Magento Extensions"
- "Free Magento Extensions"
- "Magento Themes"
- "Free Magento Themes"

and similar goes for `Prestashop` & `Woocommerce`

Which menu structure should I implement in terms of SEO friendliness? or I should adopt a new structure.
Please do suggest.