hiya, i could also just point out that failing the sva isnt that big a deal, apart from the test fee, and the hassle of rebooking. i had two failures on the same vehicle a good few years ago , 1st time because oil got onto the front discs somehow, 2nd time because i thought sanding the same pads would make them clean enough rather than buying new pads-stupid. but on each occasion, the tester almost worked with me to get the car through, so all im saying from my experience, if it doesnt pass 1st time you should get all the info you need to pass next time!
this was the test centre in oldham, the one that caterham use near london is a lot busier so may not be as helpful?
as long as you're driving to an appointment at the test centre your insurance should be ok. a new kit car cant be registered until its passed the sva, i got pulled over by the police wondering why i was driving with no plates or tax disc, but since i was insured on the chassis number, and had the test appointment details, he had to check what i was telling him, but then was impressed he'd learnt something new!
but i dont think you have to book with the test centre closest to you.
how are you going to drive from point of import until the test though?