Design workflow management solution using PHP, MySQL

We are building a workflow management solution in core PHP, MySQL that we need to complete in time for an event. One developer is currently working on it, and it would get done in about 15 to 20 days. However, I wish to add another resource, who could work alongside, maybe in a different time zone, so that we could wrap it up earlier. As a senior resource, you would also help us fine tune any architectural, security issues we may have overlooked. My guess is that you would work almost full time for about 7 days, or part time for about 12. Please bid accordingly. This will be a fixed cost project and You can calculate according to this time commitment required, ....I will share the flow chart and the overview of the modules before we start.