ArtMetal

Hello all,
Wondering I have a new job coming up that of which I will be subbing a lot of work out. Usually I do all of my renderings by hand, but I think i need to step it up. with my cnc plasma I use coreldraw 9 for my cad side (its easy to use). It works for that but I need to do design and shop drawings for - multiple stair cases, awnings, railings / balcony's and, even kitchen cabinets. more importantly I must comunicate this all on paper for other shops, and I don't want to do it long hand.

QUESTION: what cad program should i go with, or since I'm not proficient should i do simple sketches and have an architect friend do the cad work?

thank you
matt