Majority of the pain in doing this is learning to use the app in the first place so if you have Autocad and know it , use it.

Illustrator is  called Frustrator for a reason, it is slow to learn and doesn't adapt as well as others to doing specific tasks repeatedly. I use CorelDraw because its superb at customising so the things you use often can be made real quick to get at. It also has much better curver/line/bezier tool functionality than Illy.