Hello,
From your requirement, I see your website has an issue with translation (when the Italian/Italiano be selected it will redirect to an error page). Besides that, You also want to add some function fields, change field attributes and improve the search. It's an easy task with me cause I have over a year of experience with Odoo in many modules that include Sale. Besides that, I also have many other skills like python, javascript, XML, CSS, API... And that's all we needed for this project. I am can provide you a demo version about that if we can talk about your requirement, of course, it before when we have a deal
Hope I can work with you. Thanks for your concern