you could do a search on this site for better plans but I make stands for myself.
You start with a frame 2x4s are fine for the suports
use one in each corner then use 1x8s to built the bottom and top rectangles the 55 will sit on the edge of the 1x8 all the way around so base your mesurements on those dimentions.As for height I build all mine 36" but the standard seems to be around 24-32"you only need 3 -2" deck screws on the end of each board.
Finishing it cover with anything you like nice T@G wood ,cloth,paneling or paint or stain the open stand.
Heck I'll go take a pic mind you these are new and not near finished.
I used deck pre fab metal braces@2x4s to asemble this one like 5 years ago then spray painted it Its beat up bad now like 5 house moves 20 inhouse ones.
BTW the white outlines where I used the deck hanger joists this stands foot print is 16" front to back much more stable than a 12" stand