We have years of experience in PHP and several related frameworks.
We have worked with several user-based websites with features to show online users, just as yours.
Do not hesitate to contact us if you have any questions or wish to see our previous work.
This sounds like a simple enough project to work on and I would love to get involved with it, further details would be helpful as to what "scripts" you want implementing but I've no doubt it shouldn't take too long.