Hi,
Most of the time you do not need to run a script from FileMaker, many scripts can be recreated using only PHP. If you decide that you need to run a FileMaker script, make sure that all of the script steps are web compatible.
As far as FXForge is concerned.
Our school system has been using FXForge for two years now and we have been extremely happy with FMWebschools software. I am anxiously awaiting their new update.
All the best
Joseph