PHP is the programming language of choice for web applications. It is an immensely powerful language with lots of modules that allows virtually limitless flexibility.
Here at BeMoore we have 12 years experience programming in PHP, pretty much as long as PHP has been around.
We always use Object Oriented code where possible and use PHP frameworks such as CakePHP and Yii.
We can also adapt your open source PHP scripts to do what you require.