I think you picked the right type of layout for your shop. The horseshoe shape separates the pieces of equipment and allows you to have efficient use of space. Definitely glad you didn't decide to put the machine on the wall due to maintenance concerns.

How are you going to run the power to the machine? You mentioned your going to put the phase convertor in the corner behind the table, but what you don't want to do is to be stepping over the power cord.

May I suggest that you increase your workspace area by building/buying another workbench on casters that you can put facing the same direction as the cars, in front of the garage door. Obviously leave a 3 foot gap or so you can easily pass through. This way it isolates your mechanic and machinist work.

Nice clean shop by the way.