Hello,
Although my professional experience has mostly resolved around .NET, I also have worked with PHP and MySQL quite a bit in my private life, and have developed a similar application in PHP in the past. I am familiar with both MySQLi and the 'classic' MySQL APIs. I have used most version control systems, so I shouldn't have much problem with whatever you are using.
The scope of the project seems fairly small, so I don't think these features should take very long to add (unless you need to support fairly exotic search queries).
As you can tell, I am new to Freelancer (and to freelancing in general); if you do not feel comfortable accepting a bid from an unknown, I would consider doing the project for under my bid just to help build up a portfolio. Please let me know if you have any questions about my skill set or anything else.
Thank you for your consideration.