Car insurance

£1400 is a little high...I'm thinking we got £800 or so from Swinton (on an import vehicle).  It ain't cheap, though.  Start at Confused.com and call a lot of places.  Offer to fax them old insurance statements from the US showing a multi-year safe driver discount.

Most importantly, don't assume that 1-year permission to drive in the UK buys you any time.  It can take a LONG time to get your UK driver's license, so start the process now.  Get one of those nifty books they have at all the bookstores, study for the written test (you can buy PC "games" for practice too), and then start scheduling driving tests.  It takes most people 2-3 tries to pass, and it can take a month or more to schedule the next one.  Consider hiring a local trainer to provide some lessons (yes, even if you're an experienced driver), because the testers can be infuriatingly insistent on stupid little things like mirror checks and steering wheel grip.

Buy the tiniest local car you can find...nothing else will fit :-)