Search service for performers of one-time orders

You need to create a search service for executors of one-time orders.
The essence of the service: For the customer - to find a sponsor for a one-time order (to make a banner, delivery of documents, etc.).
make a contract, etc.) at any time of the day at a cost and time for the assignment to be paid.
For the performer - the opportunity to work part-time at a convenient time for him, to perform several tasks at once, the ability to choose between the two.
tasks that can be done without leaving the computer.