I use an RCBS Ammomaster II that's set up for the .50 from the factory. I use RCBS and CH4D dies depending on what step I'm doing, just neck sizing...
I used a Lee press, Hornady and Hollywood Engineering press also before buying the RCBS. The Hornady and RCBS press are exactly the same thing, the only difference is the LnL feature that Hornady has.
The Lee press works well but takes smaller than industry standard dies. So if you want a custom die, Lee will have to make it if they can. If not you'll have to contact a company like CH4D to custom make it.
The Hollywood press is a turret and you can mount all of your dies on it at the same time. Rotate the turret to the die you want to use and do that step. You can load one round at a time or if you want to size 100 pieces of brass, lock it in place and go to work.