Nitrous works, NX, and Zex all make good kits. The Nitrous works is a little cheaper then the other two but is an great kit. Makes good power. The NX is (In my opininon The best kit.) It is more expensive Then the other two. I have had both NX and Nitrous works on my cars and put tons of them on customers cars aswell. Everyone has been pleased with them. The zex kit is an good safe kit aswell. So which every one you go with you will have a lot of fun with it. Those three are all good quality, and reliable kits. Hope that helps a little. Also when you do go to get an Kit. Try to get an Bottle warmer aswell.