If you are only gonna do a 50 shot, buy a dry kit. Safer and maybe cheaper, and easier to install. Go to http://www.nitrousexpress.com
Also, a 50 shot won't do you much, IMO. Is it for your Eclipse? Obviously it's not a turbo, or you could just up the boost and have the same result.
Also check out http://www.compucarnitrous.com. They have some pretty decent kits, and also sell all parts individually.
I use their "street heat" kit. Although not the safest, if you are careful and not greedy you'll be fine. It sprays through the mass air meter, recognizes the severe temperature drop and adds fuel. Not the best way to do it, but I have put25+ bottles of a 80-120 shot through my car and have not had any problems. I don't know about your car's internals, so don't take this as a recommendation.
Ah, found this at compucar, their import efi kit. It comes with jets for a 50 shot. Here's the link: http://www.compucarnitrous.com/import_kits.htm
With a 120 shot, I went from 15.0 @ 93 to 13.50 @ ~106.
Hope that helps.