If you’re building a 4 x 8 layout, and you just don’t want ANY angle braces on the legs, I suggest using 2" x 1/8" steel angle iron. The weakest point will be where you attach the top of the leg to the layout. I would recommend, for each connection, four bolts in the 3/8" diameter range arrayed in the obvious way.
Cost will likely be $50 or so, including the hardware.
Ed