Go to Jackson's website and you can get a list of retailers.
The way I understand it, it has nothing to do with fuel management. It keeps things cooler, therefore giving you another pound of boost. The only real drawback is that you have to fill the bottle when you fill your tank.
I hope I helped
It comes with an adjustable boost level controller. They tell you not to F*** with it, but I adjusted mine so it comes on with just a little boost. It's not connected in any way with fuel management, but does help with overall tuning by cooling the charge and allowing you to run leaner mixtures and/or moderatly advanced timing without detonation. I bought it from Jackson, even though it's listed for Honda applications, the jet fits the pre-drilled hole in the back of my JRSC manifold. That saved having to remove the blower when drilling and tapping the hole, As far as I know, this is the Aquamist Stage 1 kit so if you look for that unit, you may find it cheaper somewhere else.
That is a potential issue, I have heard that uneven distribution is the reason JR doesn't sell this product for the Focus. They may just put the hole in all their manifolds as a matter of course. While the pre-drilled hole is in the middle of the manifold in what seems like the most logical spot I don't know how to tell if the spray is getting evenly to each cylinder. I have thought of drilling additioal holes and installing a bank of smaller nozzels to widen the spray pattern but the system works well the way it is setup. I know that it is effective-I experimented running 42lb injectors/recal mafs (without a chip to pull timing) for about a week and the water injection stopped the severe detonation I was getting completely. I like it.
I can tell you where to get the Auquamist 1s (which is the OEM version of the JR kit) for $420. They also have more advanced kits that, for example, allow 3D mapping of the load/fuel/h2o if you have a computer (Pectel) that can handle this function. PM me if interested and I will send you the contact info. I think aquamist's site is www.auquamist.co.uk