Hi dom - There are 2 styles of nitrous kits, wet (adding fuel), and dry (no fuel added). I prefer the wet system over the dry, because you are not relying on the carbs to componsate for the addition of nitrous, and you won't lean it out.
To answer your question, Holtzman's kit is by far the best I have put on my toys. His fuel jets plug into the carb boots, to add fuel, and the nozzles are mounted in the airbox. His kit uses the stock fuel pump(s), and hooks right in to your 12 volt system.
I have 2 nozzles spraying 60 horse into the motor right now, and I get about 15-16 times, where I hold it for 6-8 second bursts. By that time you are easily over 110mph.
If you go with his standard kit of 30-40, the bottle will last much longer.
I am at a peak of 9,700 without the nitrous on, and about 10,200 with the NOS on. I kept it down in case of track spin.