Dear Sirs,
I'm experienced in both AJAX and php (and asp), Jquery is one of my favourite libraries, and I believe I understood Your requirements.
On top of that, I'm used to deal with major browser differences, and thus I'm able to make Your scripts running on IExplorer, Firefox, Chrome and Safari (and some others You define as critical).
About the (email) notifications You mentioned, we should study different alternatives like using the email of Your site/domain or configuring some ad-hoc gmail account just for this purpose.
Please keep in touch,
Prof Dote