I guess the following echos Craig's reply.
-Use what ever CAD you wish as long as you can draw a circle, a line, an arc and few other things and it can save a version 12 DXf.
-Lazycam Plasma module works and provides good code. READ the manual on how to use it and you will need the Pro version to use the Plasma module.
There are better programs out there.
-Don't use the latest version of Mach3 try 062 and below. Read the manual for Mach3, watch the available videos, and understand the controlling software.
Buy CNC Programing Handbook by Peter Smid and study it.
-Plasma is a different machine in itself. You need to understand how to use it
so educate yourself.
-Know what you need to buy or modify and decide what you want and after you have selected the item you'll need to pay for it!
CNC is not pug and play and touches on so many different topics. The learning walk is long and the path can be windy.
Only you can walk the path..................if you don't desire to do so, consider taking up Golf!
My advice and you asked,
RICH