Making your own tank just isn't cost efficient, I have done a bunch of research on it, it wouldn't be hard to do if you had the materials, but you will end up paying more than if you just went and bought one new that might even come with a hood and still be cheaper. Do a search on this forum for aquarium building, or DIY aquaurium and you should come up with some posts that were just posted in the last couple of weeks or so that asked the exact same question you are.