I know the feeling...
Installing Apache and Php on your machine, unless you intend to become a server yourself, is a waste of time (and pretty complicated if you are not fluent with Unix/linux...)
My advice:
- Buy a domain, rent a LAMP server, get a good FTP.
- Edit your files with Notepad++, upload them to your server (THEY have done all the hard bits!).
- VIEW you files through a browser.
- EDIT them on your machine, then re-upload.
This could be called "on-line development".
That way, you can see both: the sources (Notepad), AND the result (browser).
One little "risk" using your one machine as a server: YOUR php set-up may not be the same as the final client. You may have to review ALL your code once you install it to the client...
I develop directly on my client's server. No surprises.