I too am a cncpro user (about 2-3 years now) and it has worked well for my applications. However, I am very disappointed in the lack of or should I say no support for the program. The price however went up to its current $199.00. What really ticked me off a long time ago was there is no manual for the program and if you want one, its another $25 or $30 bucks.
I am going to try Mach 2 and so far it looks very intersting and it's $50 cheaper then cncpro. The manual is outstanding!!!!
For DOS I would look into turbocnc or cnczeus.
taus
www.cuttingedgecnc.com