I race on Racetec's and have no complaints about them whatsoever - excellent tyres. I am not sure how quick you are so, you might not get the life you are looking for. I get approximate 30 laps out of a set at most. YMMV.
They need careful management with warmers and you need to keep an eye on the number of heat cycles you put them through..normally recommended 4-6. If you're wanting 4 days out of them then you might be better off with some sticky road tyres such as Pilot Power 2CTs which, IMO, are more than enough for most people for trackday use.