Need a freelancer for maintenance and support of database oriented website

Looking for an expert, a company, or individual with about 30 - 50 free hours a month to maintain, support, and ongoing development of a database-oriented website.
The website has been developed, but need to upgrade, modify, add/develop new features from time to time.
Need to be able to work with a team, and on specific tasks.

The work is per task with a budget and schedule. From time to time, new tasks will be presented, and the budget will be assigned accordingly.
The website is in English.
More details will be shared later on with the potential candidates.