Looks like SVA imports in Dover, personally I would avoid buying any car from them. I have heard a few stories about this place and the owner to be honest. (cant really say on a public forum)
I went there a few years ago, was looking at px my uk Celica for a GT4. The guy was rude, couldnt be bothered attitude, priced up my car from just a glance, didnt really know what he was talking about.
A friend of mine bought a GT4 from them about a year ago. All sorts of engine problems starting going wrong just after buying it. Turbo, seals etc, they didnt really want to know after it had left the garage, it took him quite awhile to get them to fix it.
Personally I would use one of the importer guys on here to find you a Supra, but thats just my opinion