Man, the wood grousers would be easy to do. I would use white or red oak, they can be bevel ripped on a table saw, then cut to length on a chop saw. As far as materials, I would talk to Boise Millworks in Garden City, or Intermountain wood products, in Boise. IWP would sell to you directly as a cash customer. You would start with 8/4 material and rip down from there. I would allow a 2” x 2” x 32” blank for each grouser and go from there. You may be able to snag enough dunnage or drops from Boise Millworks to make enough grousers.