Water injection seems to be coming up a bit..
The aquamist system was used widely by the WRC teams in the last few years until being baned this year!
A very good system but at about $1200.00, NOT cheap..
They will sell just the nozzles which are better than the finest of the agricultural (flojet) ones. They produce a very fine mist and are about $40 / jet.
The flojet type of pumps can be used. Use the 100 psi unit if the water is to be injected after the turbo. and should be just after the intercooler alowing the mist to fully vapourize before the maifold.
I`ll be using somthing along those lines when i get my engine finished. If anyone else sets up a system id love to here how they get on., Simon

(EDIT) sorry sikdatto, i looked at your links after posting, a link to aqua mist from there.