Prestashop Modifications

I have a foundation book webshop that uses Prestashop as it's base engine. It currently has a theme loaded and some previous modifications has already been applied, yet I am in need of more modifications before it can go live. I need the following things done on the website: 1) ISBN number field needs to be added in the backend on the product page and shown on the product page, also when ISBN number is not filled in the backend, the whole ISBN label should not show on the product page. This is also needed for another new field and label called "Article number" where the same rules apply as stated for ISBN above. Currently you can only put the info on the product page like Name, Reference code, EAN and UPC, basically the default fields. (See example from someone else here: [login to view URL]) 2) Both ISBN and Article numbers should be searchable in the search option as well and shown in the invoice generation to PDF. 3) Both ISBN and Article words should be shown in the translation section of PrestaShop, so it can be modified when adding additional languages to the site. 4) At the checkout page, one can only select either if it's a Male or Female checking out when filling out the personal info (for account creation or anonymous checkout), but I need to have a third option where it says "Company" which should be shown on the checkout page, and if company is selected a field should appear where one can fill out the company name as well as a VAT field should show up. If the selection is either Male or Female the VAT and Company name fields shouldn't show up since its just a normal non-business owning customer which should not be bothered with unnecessary fields. 5) Currently the contact information on our website is found below in a dark-green bar which comes with the theme, but the address should be shown cleanly (white block) on the contact page. 6) At the place of the contact information (dark-green bar as mentioned previously) there should be a "latest tweets module" (see if there is a free version or whatever, check in with me to see which twitter module should be there). 7) Currently on the checkout form there are 2 address fields, it's currently something like this: [ ADDRESS FIELD ] [ ADDRESS FIELD2 ] But i need this to be: [ ADDRESS FIELD] [House Number] Where house number should be max 6 characters and also mandatory to be filled out. That pretty much sums it all up. NOTE: Please ONLY respond if you really know _PrestaShop in and out_ and know the technical aspects of it. Also you need to be SERIOUS and have very good COMMUNICATION SKILLS and also know what and how to work with Git, everything you do should be committed to a Git Repository which is MANDATORY, the commits should be done by the common Git rules like "Only commit working functions as a whole in 1 commit" so that means, do not commit a change you made in 1 file just because you edited something that does not make the whole function complete. Further details will be given once project is accepted and confirmed. Asking questions is a sign of starting off with good communication. So, please feel free to ask your questions using the Freelancer Chat also if you don't understand something I have written in this description. Thanks.