php edit custom. of Mibew Messenger livechat php opensource

[login to view URL] is an open source live chat written in php, I need some small customization(I will provide graphics), and the main thing we need is that the php have a "leave message" when there's no one online, that send email with fields, but is written in a way that send from aan email that is setup on php file, with it's fields. we need to do it in a way that the from (email field) will be the email that the customer write on the form, and not the one set it up on the php. it's like to put a php send mail inside this is the job. I need expert in php for future or montlhy job in the future, so please no team but good expert that I can chat on skype or even talk a bit in english even if not perfect I am not native english too so no problem. if the php expert is also an expert in CMS customization will be better for future projects.