Expect to use in excess of 1TB of bandwidth a month.
Bandwidth isn't a concern I have a couple GigE circuits available with 200-300mbps of spare capacity.
Wondering if there was a web/PHP/MySQL setup already to run the pool or will I have to re-invent the wheel.
you'll have to reinvent that wheel, though it isnt big.
Its the only thing that makes every pool different. They all made their own app/program/script between bitcoind and the users.