Got my new wheels/tires from here for less than you buy just the tires!
http://cgi.ebay.co.uk/ws/eBayISAPI.d...#ht_1829wt_704
Got Bowtie SC's for our dirt track at Adur, some worn standard tyres for ragging about and some new standard ones (Above) that I'm going to modify, the thing to do is to cut the outer U shaped tread apparently to get better side bite....handy to know if you have to use the kit tyres for a series