I'm leaning towards the GTR, with a 425 bhp Chevy V8 from http://www.amerspeed.com/ultima.htm

My car maintenace experience so far amounts to changing the front brake disks and pads and a radiator, so building my own car should be interesting...

Oddly GTR ownership probably works out cheaper than the TVR. Insurance costs are lower and you don't have the £25,000 depreciation over three years that the Tuscan attracts.

A while ago I sat down and worked out how much running a Tuscan for 9,000 miles a year costs over five years. I seem to remember it was over £10,000 a year (without anything major going wrong). After doing those sums I was even tempted by this for a while:

http://www.p1international.com/