I'm going to have egg on my face if this project flops, but I plan to update this as I progress. My plan is to make a hood covering the entire top of this tank

Note that there are no square corners on the tank or the stand, so a simple box hood would probably not look great.)
First: I made a template, using photo matting, which I already had. It looked like this:
Then I visited Home Depot and got an 8' long oak 1 x 4, an 8 foot length of oak quarter round, and a 2' x 4' piece of 1/4" thick oak plywood. Today I cut out the pieces for the frame of the hood. Note that the curved piece will be on the top, the sides are 1 x 4's, and 1/4" plywood will fill in the curved front and the top. I will assemble these using "finish" type stainless steel screws, in counter bores where they wont be hit when I round over the corners with a router. The parts laid out are:
Tomorrow, I hope to assemble the frame!!