Update website with specific new functions

We require a few additions to our website [login to view URL] to include: Facebook login, Rotating header images on our index and sign up page (code exists). The user home page needs some instructions to help quide the new users. Some of the code exists.. at one time it worked. There are a few other changes associated with SEO but we will wait on that project. The user home page section will need more specialized programming but almost 100% of the code exist or has worked at one time. Even though we used one of Freelancer's most highly rated Indian firms to design the site our USA based Freelancer tells me the Facebook login will be extremely difficult and he does not want to do it. So we are again back on Freelancer. We were informed our company is now in the top 10,000 employers on Freelancer and we really do not understand that. The next phase will be creating apps for the android and iPhone. If your firm is capable it would be great if you can give a quote after you see the site. You must prove to us you have and apps published and working. We will post that project as well. If you are a small firm and will ask for milestone payments each time you do any work please do not waste your time. If you do not submit the completed NDA / confidentially agreement we cannot consider your bid. We have invested over $50,000.00 on the site. The site is completely unique, and 100% custom. Provided the site does well there will be excellent opportunities in the future. We have every reason to believe the site will do extremely well as we researched the concept of over 1/2 year before we decided to go into production. Good luck