Can OpenCart do this?

Hi

What I am wanting to use it for is a product that the user customises through their web browser and then adds to the cart at the end of the process (if they are happy with it). This basically means that the user ends up with a thumbnail of their customised product, and they then pay for this- meaning the traditional 'list of items' is really just a single item on a page priced correctly and a thumbnail of their customised product. (The real product is sent out later). They should then be able to add multiple products to the cart and then delete or whatever products from the cart.

ALso can I share the user DB with a VBulletin user DB? (i.e. one login for shoppingcart and forums?)

Thanks