Still looking to get a kit car.
What is the best type to go for? this is what I need:
1.) Cheapish Tax
2.) Cheapish Parts
3.) Fairly Reliable
4.) Easy to tinker with 
5.) Half decent engine
6.) Under £6k
I am thinking something like this:
http://www.pistonhea...ales/599753.htm
Knowing naff all about kit cars, any advice much appreciated 
I'd recommend the Tiger range (having just sold my supercat). I'd avoid anything with a pinto heavy, old technology

, and bike engines arent for everyone - great for track work not that practical on the road imho.
Tax will depend on the plate it's got - registered as the donor reg the emissions and tax for that will apply, registered new then the emissions and tax for that year/engine size of vehicle will appy (i.e. anything post 94ish will need to pass a cat emission test - anything registered after 2001 will fall into the new government tax scheme) - Q plates are 'visual checks only' for emisisons etc etc
Mine was registered as a 1981 as per the donor vehicles year (although sva'd in 2006) and was £185 a year to tax.
Most 7 esque vehciles are really simple in design and easy to work on with basic mechanical skills, parts will always be cheap, most of them are based on fords.
The 2l zetec on the weber alpha setup will kick out about 165Bhp, awesome performance with go kart handling, plan to have to have the carbs set up once a year as they seem to always go out of tune.
£6k should get you a decent avon, or supercat with a 1.8 or 2.0 zetec.
The most important thing is knowing what you are looking for when you view one, as a couple of people have already hinted at, its all down to the quality of the build!
See
http://www.tigerownersclub.co.uk or
http://www.locostbuilders.co.uk for some useful info.
Good luck