Wow! Are you really updating that much PHP code to out pace 5.3? I am a bit confused though.......what exactly do you need? Do you need a specific version of PHP? or do you want the latest and greatest linux server to run an older version of php?
If a latest and greatest distro of linux supports the latest version of PHP (lets say 5.5) but your code currently only runs on 5.3 or 5.4, just manually install the version of PHP that your application runs on ( 5.3 or 5.4). You can still get updates for that php version from the repo's
Locally on my PC i have Fedora and I I have PHP 5.5 running.....