I'm not sure if you saw my small table build....maybe some ideas there for you, tho yours is going to be much larger. What wall thickness on the square tube? 1/8" should be sufficient, tho 3/16" is more stout. I would plan on getting large casters. I really like my 5" harbor freight casters, tho you might want locking ones with the large table. I like having square corners on my plate so I can use it as a 'square' when assembling things. Make sure your plate top is cut square. I'm sure others will have some good ideas to add.
http://www.everlastgenerators.com/fo...-Welding-Table
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