Nitrous for my carb'd A20A1

I just bought a ZEX nitrous kit. The kit is for a efi car and my car is carb'd. Also the kit did not come with everything so i have to buy some of the parts, like the purge kit, some of hardware, and the jets to inject the nitrous. I do not know much about nitrous kits. So, what is the difference between a dry shot and a wet shot? An which is better to get? What size shot should I get that would not blow up my motor if I was to use it for more than 3 seconds (I am thinking like a 25 to 50 shot. Something that won't blow my motor.)? If anyone has any opinions on my questions or on stuff that i missed that is important or about anything (from brands to what I might need to do to my motor and anything in between) would be great.

thank you all