Sure, here are some links :
Tiger :
http://www.tigerracing.com/
Radical :
http://www.radicalsportscars.com/
Noble : http://www.noblecars.com/home.htm
Ultima :
http://www.ultimasports.co.uk/
Ariel : http://www.arielmotor.co.uk/04/frames.htm
I'm actually surprised that as a Brit, you're not familiar with most of these - I believe they're all made in Britain, which is a *great* place for focused kit cars and no-nonsense sports cars. TVR, which is one of the better known British sports car brands, is one of my favorite makes as well.
I'm pretty much into cars. Can't afford one of these machines unfortunately, Singapore levies taxes on all cars, making them easily three times as expensive here as in the US or UK. I drive a highly modified Subaru WRX, my dad drives an Evo (Mitsubishi Lancer Evolution VII GT-A) and a 2nd gen Lotus Elan turbo SE. We've pretty much always had one fast car or so around the house, including a 911 many years back. The only crappy car in the house belongs to my mom, that's a Kia Picanto.