Appreciate the response Rives, helps a lot to get some good information and bounce around ideas.
The main breaker kit would be a nice addition, thanks. Guess if I got a lug center with the space for 8 breakers, I could use 2 slots on a main breaker, 3x 2 slot 20 amp breakers, for each duplex.
Really the outlets in the ceiling was just cosmetic, I could surely just tie the cords up neatly along the ceiling and down a wall to the outlets.
I am leaning towards the outdoor style. Nice to be able to just unplug it and remove it from the wall, leaving behind only a single outlet. Hard to say how long I will use the room, and if I tear it down I don't really need all the extra outlets and wiring in the wall.
So this is what I am thinking now. Please let me know if something sounds poorly designed.
Garage has a sub-panel already. I will add a single 50 amp dual pole breaker into the subpanel, run 6-3 mmb to a single 50 amp outlet, not a very long run maybe 15'.
Wire a 50 amp range cord into a outdoor lug center. 1x 50 amp main breaker. 3x 20 amp breakers. Using conduit and 10 awg thhn, add 3x duplex 20a outlets/w boxs.
Then I can just plug and play the lug center as needed... hopefully