JAC Chat Removal & Message System Implantation

I need a developer to completely remove the Chat feature that is on my web site and replace it with a message system. I am very limited as to what software I can install because I am currently only on a shared hosting plan. Once I get lots of traffic, I will move to a better hosting plan. For now, I like the cheap hosting :)

Attached are images as to how I vision the message system to look or work however I am also looking for the developer to maybe help with design and functionality.

The purpose of this message system is to allow members to communicate before, during and after a transaction. It is NOT the main feature of this web site service so I am not looking for a message system on steroids.

I also want an automatic e-mail sent to the memeber when a message is sent to them that lets them know they received a message from a member on JAC (i'll supply the verbage of the e-mail but it will look like other automatic e-mails).