High compression pistons, where to get?

I just bought a fmf fatty. I'm going to go with a fmf q seriers silencer. Ken recommend toomy but they are $$$. Carb is going to be a kiehin D slide 34mm. Ken is going to do the rest.
I will probably do the 400ex rear shock right away since its such a cheap and easy mod.
Down the road I will get an extended swing arm. Not sure what length I will go with yet.
I'm not sure if I should go with a 13 or 14 tooth front sprocket. I'm sure it will have plenty of power to put a 14 in it but it might be too tall in first to start out.
 
I'm not sure if I should go with a 13 or 14 tooth front sprocket. I'm sure it will have plenty of power to put a 14 in it but it might be too tall in first to start out.

What size tires do you run?
I run a 15 tooth front sprocket / 40 tooth rear with 18" rear tires and i can launch in second gear, so if ken is gonna work on the cylinder 14 front sprocket shouldn't be to tall in first to start out(maybe with huge tires????)
Just saying;)