Just get a Class 2 for now, as otherwise you need to keep paying the costs of a class 1 renewal every year. If you decide to go Professional, then get a class 1 before you do anything else to make sure you can get it!
Cranfield is a great place to train, precisely because it is so busy! You get a real workout on the radio, and it teaches you good circuit discipline, and good ATC procedure. The traffic can occassionally be a pain - I've been stuck at the hold on occassion for up to 15 minutes, but it's not normally a problem - particularly if you do most of your training at the weekend / evening when the big schools have gone home.
There's plenty of places you can study - PM me if you want more info on a couple of them. I did my PPL at Cranfield, am half way through my ATPL's, and will be doing my CPL & IR there - I know the place pretty well!
DW