Did a bit of ringing round today and research online at work today, err I mean in my lunch hour just in case my boss is reading this. Alfaworkshop, Alfashop and Autolusso in Bournemouth (I just looked there for another comparison) all came in at around £500-£550 for the cam belt, tensioners, balance belt etc plus water pump and variator. The Fiat and Alfa Romeo Specialists in Bury St Edmunds wanted £500 for just the cam belt etc plus about another £200 plus VAT for the variator.
Both should be able to do it in a day and no doubt the Mrs will want to come with me and then spend all day moaning about me taking her to a garage and then go off shopping. So my decision on which one to use will be based on where she can spend the least money.