So, in the end, I put on some 18" bbs ch alloys wrapped in Yoko ad08 advans. Went to the ring, did some mega laps. Came home and dud a track day at Abingdon in the wet. I seriously recommend these tyres. They were mega in the wet and dry, and didn't wear too quickly.
Barry at www.thetyreshop.co.uk
sorted me out a great deal.
Recommend both the Tyre Shop, and the tyres!!!