Hello Sylvain,
i would like to offer you my prestashop skills. I work with prestsho voer 6 years and i made countless custom prestashop modules.
I am able to develop for you even your module. I will need more informations from you. Do you already have any specification ? (How this should look in administration, in product detail and so on...)
Thank you for your time,
Kind regards,
Jarda Nalezny