Just use pine alot cheaper than oak trust me on that! I made an oak stand man that was expensive but that was for a 30 gallon, if you want the oak look build the inside pine and outside a oak veneered plywood.
I think that will keep the little rascal outt there.
RR the reason i didnt cover up the trim is the fact the wood matched great with the tank, and also i didnt want water getting inside the trim from dipping and running down the tank. This way its flush and easier to get the water out otherwise the water would sit in there and eventually eat through the polyacrylic (because of salt) and i didnt want to make a nice stand and have it warped and ruined in a year. Thanks for the input guys keep it coming!