Solidowrks student edition. If you buy the student edition you will run into the problem that the full blow version can not read student edition files. I ran into this problem when I took it at the local junior colledge.
Also the software is only good for 2 year's.
If you look at Rhino3D you get a discount if you are a student. Plus it's the full blown software.
I've used AutoCad, Solidworks and Rhino. If I had my choice I would go with Solidworks. Reason being, I mostly work in 3D. Assemblies etc. I find Solidowrks easier to use and I do not have a long set of commands to remember. Just point and click.
Rhino I'm slowly learning and in some ways it is like AutoCad. You need to learn commands. But when I'm stuck I can go onto their wed site and under support access the news group. Post your question and, in an hour or so you get an answer. I've had every question except 1 answered.
As for the 1911 check out
www.cncgunsmithing.com
I believe that he alread has a solid model available for a 1911. But the model was done in solidowrks. You can check out the site and see what he was able to do with the program.