a lot of times it is best to compliment the port meth injection with a larger jet after the mafs in each intake pipe. you can run just the jets in the intake pipes but the distribution will not be as good as having a jet in each port. the best place for a simple setup is between the maf's and the throttles, this way you don't have to worry about the engine pulling meth under vacuum.
Edit: Read the bottom of this page it details location and sizing(this changes with different systems due to the differences in pump injection pressure)
Aquamist Kit Info