You guys must have nicer lumber where your at, around here I would be at the lumber yard for two days trying to pick out straight ones, and the pile of crap ones would be three times the size of that tank.
If your looking to do a wood one then make sure you get yourself a good chop saw. Second inspect every piece of wood. Made the mistake of just ordering a bunch of wood from homedepot and having them deliver it on the last pond, about 1/5 of it was unusable and half of it we had to make work.