We have 2 heights available for our base cabinets. We have a 35" and 27.5" high.
Your base cabinets should be 35-inches tall if you want to use them as a workbench.
Our base cabinets can either be 32.25" or 16.5" wide.
Our base cabinets are 22.5" deep.
The leg room should be a minimum of 24". This allows plenty of room to move your legs around while sitting down.