skadate customization

I'm running latest version of skaDate dating software. I would need someone to make the following customization for it: Free members are restricted of sending only one message per 5 minutes. If a free user tries to send message more often, he sees text "You are a free members. Free members can only send one message per 5 minutes. You must wait X seconds before you can send another message, or you can become a full member and send your message right now." Where X is the number of seconds he needs to wait and the X is updated with JavaScript to count down in real-time while the page is open, and "become a full member" is a link to the full membership option purchase url. The site is not yet published, so I can offer you server access.