I need maintenance and improvements for my website.

I have a reviews website www.saudeconsulta.com.br for which I need eventualy services of maintenance and improvements. Right now I have some issues pending like:
- improve the system of upload of the database;
- create a system for download of the database;
- improve back-end menus and its features;
- implement a system of voting on users reviews, like youtube;
- create a system of management of keywords for segmented ads;
- help create strategies for ad exposition;
- clean errors related to characters setings
- create an option of reply for the person reviwed;
- create some automated FaceBook posting when an user post a review;
- deep inspection for improving the whole website functioning, mainly on the database. Sugestions will be very welcome.