hi there Walter
I think there has been a couple of bits on here regrading plasma

the thing to do is gather as much info as you can, read some of the router build logs and draw up a simple design then start a new thread/build log with your drawings so people can critique and point out any possible problems etc

the trend tends to be you will do lots of amended drawings have lots of discussion about the finer points and eventually start buying components with some confidence as a result