Sometimes I see these under "drip irrigation". Sprinkler warehouse offers them under "microspay"
http://www.sprinklerwarehouse.com/Microsprays-s/135.htm
Using your favorite search engine, you should be able to come up with a good variety of these things.
I use a lot of these types of sprinklers for flower beds. They tend to operate on about 20psi water pressure. I don't know what pressure your current system operates, so best would be to find out.
Consider, also, the need for filters. These things can clog easily.
I believe the response from jasoninct is accurate. Make sure your existing system can support additional flow rates required from these. This is in addition to determining compatibility with pressure.