I have used Kimborough spurs both 48p and 64p in my s1 and r1. I've also used the white 3Racing ones and I think Robinson racing?? I'm not 100% if that was the brand or not, but I've use a third brand.
I think I'm using a 94t 64p in one car and either a 69t or 72t 48p in the others. I'm generally running gear ratios from 3.75-4.5 FDR, depending on the car.