The easy part is designing and constructing the pages. PHP will make it easier but honestly anyone with Dreamweaver could do a decent job.
The hard part is populating and updating the database. Either someone has to spend a lot of time checking/updating each item or spend a lot of time developing an update method where the excel files containing the item stats can be fed to the database. The problem with the later is the item modifiers in the excel files are not all in a consistent format. Also labeling of each modifier such as "Enhanced Damage" or "To Attack Rating" would most likely occur on the HTML side.
I would forgo the idea of loading item stats into databases.
Instead I would use the PHP server to facilitate a website without frames.
White item pages are easy to build using excel which are currently built sitting on the web server. However the other item pages I believe are best updated manually. That isn't to say someone can not automate all of it, but I wouldn't
