With your application I would also go with a wet system. If you go dry you will need a way of adding X amount of fuel throught out the rpm range that the nitrous is spraying. Personally I think its more trouble than its worth.
If you are trying to be budget minded put on of our Brand X wet systems on the car. The quality is great, it will flow up to 200 hp so you can grow with it and we have the best technical service in the industry.
If you want a plate system check out our Nitrous Outlet plate systems for your application.
Wiring it on the cruise button is doable but you need to get a schamatic for your car and trace down the wires. I would still suggest using a windowswitch with TPS activation and just wire the button as a contact break.
If I can help you in any way please let me know.
Dave