I suggest birch plywood too. Oak plywood has a very porous grain, which could be a problem when you laminate, while birch is always very smooth and usually very flat. Any plywood is pretty immune to shrinkage/swelling, because of the crossed grain plies. Birch is just about the standard material for professional cabinets too. If you are just skinning over the structural frame with plywood, you don't need 3/4 inch thickness. I think 1/4 inch is too thin, so a good compromise might be 1/2 inch, saving some on weight and cost.
Plywood can run in any direction, as far as strength is concerned. I think vertical grain looks best, but if you laminate it, it doesn't matter.
If I were to do this I definitely would not use a wood hood like that. I had one on a 120 gallon, 60 inch long tank, and it was a huge problem to remove and reinstall when doing major maintenance. Plus, I never had good lighting when pruning, cleaning, etc. And, a rimless tank looks really great completely open on top, with a suspended light above.