OS chooser

I want to make a little web app to help users of my linux shop choose the right OS for them. The idea of this app is that they select the processor that they have and it then displays the available OSes for that processor architecture. The problem I am facing is that it has been a while since I’ve coded in PHP, Perl or anything other than CSS. I’ve ideally like to make this app in AJAX as this will instantly work without having to reload the page or sent them to another page to display the information they need. Another idea I have just had, literary now as I am writing this, is to have the shop sorted into distros like it is now but also allow them to display the OSes by architecture aswell. Both will require some planning.