what commuta said
i dont have a lot of experience with nitrous on bikes but i do on cars. i used zex, nos, nx, tnt and top gun. they are all basically pretty much the same. the key is not to get greedy and have the right "set-up".
a buddy & i put a zex kit on his busa. it was easy to install and made good power. he is going to get it tuned though. i like the fact there is no button to push so you can concentrate on the road. it uses the tps to activate the nitrous at full throttle. nice setup imo.