I think that it would be best with 4 channels and a Norvel .074. DuBro makes a steerable nosewheel that should work nicely.
You don't need a CAD program to print it. It is already tiled in the PDF file or, if you prefer, I have a program that can resize it.
If you want a good CAD program that is easy to learn, try Turbocad. They used to have a free version at
http://www.turbocad.com , but I can't find it there anymore. The free version I have is 5.1 from 1998, but you can get version 8 for around $10 on eBay.