Since this is a corn rack, the tubs will be 32qt. I believe thier dimensions are (34 3/4" x 16 1/2" x 6") . So thats 34 3/4" long, 16 1/2" wide, and 6" tall, right? Ok, this rack will house five tubs with an extra shelf on the bottom. So wood supply list (and please someone suggest a type of wood that is water resistant, won't bend under weight, won't sag, and is fairly inexpensive.)

Back Piece
Side Pieces
Top piece
5 Shelves
Sliding Bars (so tubs can slide in and out. And it will keep top tight to shelf above)
Locking Pins

Can anyone give me the dimensions of the wood I'll need?