Ah you are at the point where it is hard to justify a CNC lathe if all you expect is to run 5K worth of parts thrugh it a year. Even a home built job.
I'd strongly suggest looking for a used machine and see if you can get one for around your price point. That is a used CNC lathe in runable condition. I'm not sure you can get to where you need to be buying and retrofitting a conventional lathe. It is not that the conversion is imposibble just that you are describing needs that can be best meet buy a machine built for what you need.
In other words coming up with a automatic collet or chuck for your bar size and a tooling turret leads me to believe that you really would be better served gettting a used machine that has the features you need.
The other thing to do with the lathe is to find other work to justify its existance. You certianly have an issue considering that that parts volumne is rather low.