mortar tubs can be found at Lowe's or Home depot...
measurements are honestly best done to suti your needs but tons of good sites...
http://www.rodentracks.com/Large-Tub-Rat-Rack.html
http://www.arbreptiles.com/cages/rat_rack/ratrack.shtml
just go on the Mazuri site and look up dealers.
For small production, I highly recommend spending the extra and buying mazuri 6f feed.