I am going to install a 240 outlet in my shop. I don't currently have a need but am going to install one. I do have a dual voltage air compressor that is doing just fine on 120. My small mig is 120. What are the recommendations as far as amperage and outlet type. There seems to be many to choose from and as I don't have anything that uses this I don't know which one to put in. I did buy the pictured unit (per the guy at Lowes). I have some 8awg wire. Outlet will be less than 2' from panel.
The problem with this thinking is whatever you buy may not work with the equipment you eventually buy.
the circuit is sized based on the equipment specs.
Since you dont have any equipment, you have no specs to go on.
Now the outlet you bought is useless for 240v equipment because the neutral is not needed. Not sure why the Lowes guy told you to get that one. If you did end using this with say a 240v motor, you would need a different plug than what would come with it since the neutral is unused
Since the panel is so easily accessible, why bother getting anything right now? Why are you bothering with this?