Develop a step by step prestashop module

We are professionnal smartphones and tablets repaires and want to upgrade our "At home" activity by launching a prestashop website to allow our clients to order their repairs online. What we need : A module that would allow the client to access the kind of product he needs (a repair) by selecting successively the type of product (smartphone vs. tablet), then its brand, then its model, then its color and finally the repair he needs (broken screen, battery replacement, ...) The process is really similar that the one used on this site : [login to view URL] We also want to let the customer the ability to send us his phone instead of asking for a technician to come at home. In this case, the price would be lowered. Moreover, the module must take into the account the product(s) already in the cart to offer discount(s) on a second immediate purchase : - the customer adds a second repair on the same device, he then gets a 50% discount on the second product ; - the customer adds a second repair on another device, he gets a 10% discount on the product. Of course, the module must be dynamic and it should be possible to define the products concerned (why not by selecting categories), the discount rules for us to manage (CRUD) in the admin. We are opened to suggestions in the use of any other solution or proposition you could make us so help yourself. NB : we had to put a budget on the ad but we'd be glad to hear for a great proposal and pay more if necessary.