I am sure that Sussex is doing or cooperating in CPL training. they are a nice bunch of chaps as I remember. I knew an instructor there who went on to Oxford and he was top notch.
Shoreham is an excellent place to learn from. The ATC is proffessional and helpful. It can be a busy airport and you will get put through your paces. They want your money and are prepared to give value. Give both Sussex and Sky a ring. That will only cost you a few pence. Good investment if you ask me.