PHP/MySQL: Its not a very good solution for web applications - its a great solution.
The problem you may face is gettign you Access/JET data into MySQL (Its realtively easy, just an extra hurdle.
Access/JET is not a very good solution for WEB sites, if you are expecting a lot of hits on the site (JET isn't very good as a multi user db engine)
Are there better or equivalent solutions out there, of course.
You require a means of storing and retrieving the data (thats the database side there are many contenders in this arena MySQL, ACCESS/JET, SQLLITE POSTGRES and the big commercial SQL engines
You require a means of rendering / formatting the data thats the application side, there are many contenders from scritping languages like PHP, ASP, ASP.NET, JAVA languages that run as CGI scripts like perl, Python etc....,
To a ceertain extent y'pays y'money, y'gets y'choice.
On a tight budget its very hard to beat PHP/MySQL, PHP is very easy to pick up. MySQL is "just" an ANSI SQL engine with bells and whistles
Look at the other sections on this forum for a few ideas
php and mysql is the de-facto standard for a reason. Access is a phenominal front end to MSSQL as a reporting engine, not so great for web stuff based in MySQL. That doesn't mean it can't be done, but php is easier to toy with IMO.