Thanks for all your advice. One of the main problems I am finding is that I need to replace all the body panels (this is what you get buying from ebay) as they are all in a poor state. Finding these at a reasonable price is difficult which means going to Kitspares and that will cost me about £1300 without the tub and the insides. I am not too bothered about the inside as I will just get some sheet aluminum and cut it to shape. That is why I am considering the zero kit.
I think that the 1.8 pinto is good enough for what I need at the moment I am not going to race it I just want to use it