Hi there Mr Beefy, welcome aboard.
Lots of the cars come with the active (electric) front spoiler - all of the UK cars you are looking for should have them unless the owner has removed or disabled it to fit a large front mounted intercooler.
Imports do tend to be more expensive to insure but shop around, a lot of companies are more willing to offer policies of a similar price, usually those that understand the cars a little better rather than the big generic call centres.
One thing to take into consideration is that a UK car will generally cost more than an import so what you save in insurance costs could be eaten up by the extra outlay. Also if you are looking for something specific, a black UK manual for example, you may have to wait a while for a nice example to come up for sale.
Take some time to read up on the information available on here:
http://www.mkivsupra.net/vbb/forumdisplay.php?f=69
Use the search button too, you should find answers to most of the common questions.
Good luck with your hunt for the right car.