Ubercart - Renting system

Hello,

I am coming back to Drupal after a few years without using it (last time I was using V5.0).
I installed version 7 and Ubbercart to handle a product renting system and I am having a hard time figuring out how to set up the site properly to do what I need.

Let's take an exemple :
I have a product A which cost :
. 30$ for one day rent
. 50$ for a weekend
. 60$ for a 3 days rent
. 100$ for a one week rent

When the user adds the product to his cart, I need to collect two information : The duration of the rent and the dates for which he wants the product (Ideally, I would need to know the number of days based on the selected dates). Then I want to apply the right price in the cart before checkout.

To add the date selection, I tried to extend the fields of an order, which works only in the admin pages. The users from the site don't get this field and I don't know how to make it visible to them.

For the pricing system, I used attributes to the product and used the cost of the duration option to adapt the price per day. The problem with that is that the user needs to select the correct option (ex : 3 days rent) and then he still needs to enter the correct number of days in the quantity field to get the correct price.
I also tried the Alternate SKU system, but it seems like it doesn't impact the price in the cart. I think it is used for other purposes.

Does anyone have an idea how how to handle that ?
Any module I missed and I should check out ?

Thank you for your help.
Matthieu