John Myatt is very good, quick helpful service.
You can phone them for advice first - recommend you talk to Adrian, he's their 'sax man'.
You can try Wood Wind & Reed in Cambridge - online service is good and so is the help on the phone. If you want advice, speak to Thomas Dryer-Beers, ever so helpful and knowledgeable.
Tsax is absolutely right about gig-bags, they offer hardly any protection. One of the best, and longest lasting is the Hiscox - it is SO strong. There's Berkeley - come in a range of garish colours!! and Pro-Tech is supposed to be good. None is cheap but they will last for almost ever and look after your sax.
Are you talking alto and what make? What sort of case was supplied with the instrument?