I would like to use 8020 but am not sure yet (budget will decide). I've started to draw it up a few times but could never reach a final decision on what specific sizes I could get a way with. I've never used any 8020 type extrusions and in fact have never even really examined any.
Can you tell me what cross section dimensions you chose for your extrusions for the major components, main rails and legs?
I don't want to scrimp but I tend to overbuild and in this case that could press the budget.
Oh, glad to find out that the Z axis takes a Nema23.
From the looks of your studio this should be a first rate build and I am looking forward to seeing how it comes together.