I used a sheet of melamine the 49" x 96" it was 40 bucks at home depot and you can make a 5 tub 28 quart rack out of it with melamine sides all out of one sheet i actually bought two of those sheets and made the 5 tub 28 quart rack and i made a 5 tub 41 quart rack , the 41 quart i used four 2" x 4" x 4' for the sides to hold the shelves so i spent around $90 for two racks.I like melamine because they don't sag later but there a little heavy which is why i used 2" x 4" for the sides on the 41 quart rack to cut down the weight, wiring up heat tape is easy look on this forum and you will find it.

Hope this helps you.And also if you want the measurements i used for my racks i will gladly help.