See if you can find someone who's done the rear and if your lucky somone who's done both ends, i'm 19mm front and 22mm rear which like dave says it's more oversteery but that's what I wanted as 99% of road cars are set up to be understeer biased, my front end wanted to carry straight on when pushing on,
She now turns in beautifully and if I'm in the mood I can provoke lift off oversteer