I am a fan of joomla. And also, I am a newcomer in phpfog (https://www.phpfog.com). It’s git repo support is great.
Now the point for which i am writing to notify you that phpfog is supporting joomla 2.5.1 now. Now when you are creating a new joomla application in phpfog , you will get the 2.5.1 version.
I hope you will build an app in phpfog and enjoy its advantage.