Oh, I think I see - you want to build a complete package with apache, mysql, php and your own website/php script files so the user would then just plunk (or install, I don't remember what mamp does off hand, been a long time since I threw it on my system) that into applications folder and launch the apps from within there (or I assume a launcher that you would write)...
Hmm, my ONLY guess would be is you would have to create your folder hierarchy, get apache, mysql, php to all be installed into there, modify their config files to change their folder references, then create your distributable (install package or drag and drop package within a dmg) for the user to install. The most critical would be a launcher so it would launch apache/mysql/etc for you so you can always make sure to pass the appropriate current path to the apps for the configs instead of letting them launch apache manually which would search specific folders for configs if it's not given certain command line arguments.