The Kumho's are around £83 fitted with Blackcircle tyres, good price and get a good rating.
Kev, I only did about a half dozen track days in the Elise, but also did driver training with Andrew Walsh (well known in the Lotus scene) and a guy called Don Palmer, sitting with him driving my car at Bedford was both awe inspiring and humbling at the same time. I did a Lotus day at Rockingham that was shared with a Skyline group, the organisers had to ask them to leave as it got too dangerous, so I've seen the bad side to track days too.