IIS is in NT server/2000 etc. If you don't have the IIS, you can get PWS for free, but PWS may not powerful to run a large traffic web server.
Why not use Apache? since IIS is new to you anyway, why just learn Apache, it is powerful than PWS if you cannot get IIS?
You need some component to connect php with Access.
Well, basically it seems you are going to start from scratch paper anyway.
Think about
PHP/Interbase or MySQL as database/Apache as Web Server/Linux as OS
It is more suitable for each other in this package. And they are all open source community. (some of the software copies with fee is also not so expensive)