stu I'd run the toyos or kumhos depending which is cheaper for bashing around the track. but sooner or later you will want to know "what is the best time this car can do", and the only way to find out is to put the best tyres on it. About 350 each instead of 500. Careful with second hand ones, they look cheap but can we well and truely rooted even if they still show tread depth (heat cycles kill them not wear)
lets say the dunlop and bridgestone are a second quicker than the next best tyres (possible at some tracks).....imagine how frustrating it is to try and make up that second through power, suspensions settings, different driving lines etc when you could just bolt the right tyres on.
Combined Touring Cars went from A048 control tyres to Kumho V70A and went a full second faster. Then control tyres were dropped, the front runners are buying new dunlops and bridgies, and going 1.5 to 2 seconds faster again. Improved Production still run A048 and despite far more mods being allowed (eg engines are free esp for non turbo cars) their quickest cars are slower than the fastest production cars.