As others have said getting a good paint job even with all the proper equipment is difficult! Pros will mess up too!
However I've seen many people do complete paint jobs in their garages. Some people do a good job..... but ..... the majority usually make some pretty big mistakes. If you really want a DIY Paint Job I would suggest getting some Water-Borne paint. The Reason: If you mess up the paint job you can get a wet cloth and wipe it off! It might be more expensive since the paint isn't common yet, but worth if for DIYer.
Another thing you could do is try to find a shop that would let you use their booth during the weekend. You might need to pay them something. If there is a local high school or community college with an Auto-Body program, you could offer your car for demonstration. Usually they don't use their booths as much shops do, so you might have more flexibility.