I am no expert, but the ZEX DRY KIT seems to be the way to go.
Q: What is the difference between a "wet" nitrous kit and a "dry" nitrous kit?
A: A wet nitrous kit mixes nitrous and enrichment fuel by means of an injector nozzle that is mounted before the throttle body. This mixture is then drawn into the engine through the throttle body and intake manifold. A "dry" nitrous kit injects only nitrous with it’s injector while at the same time, increasing the engine’s fuel rail pressure to feed enrichment fuel through the engine’s own injectors.
Q: What is better, a "wet" or "dry" kit?
A: It all depends on the application. A "wet" kit is ideal for both normally aspirated applications as well as forced induction applications. It can require a little bit more installation time than a "dry" kit, but is easier to tune if greater than stock HP settings are to be experimented with. A "dry" kit is excellent for normally aspirated combinations that have a return style fuel system. They are very easy to install and are a great "first time" nitrous system. It is not recommended that "dry" systems be used on forced induction engines.
You will want a pressure guage
New Fuel Pump from http://supercoupeperformance.com/default.aspx
And possibly injectors. If you dont have a chip, get one.
Check around. Quite a few guys are using it.
BTW, use the sellers here for the pump and injectors if you can.
This is my winter mod for my LX, along with a bigger MAF.