The more careful planning is done upfront, the smoother everything will work in the end. Since I was not in a rush, I took several months to think about it, read other successful and unsuccessful projects on the web, measure things here and there, evaluate the space and create a very detailed plan with a computer. Here is the schematic of the setup, created in Visio:
Along with that, I created a plywood cut plan, which helped to minimize waste. Going back and forth between the schematic and the cut plan, I optimized the size for my future tank construction. Originally I wanted to keep the length of the tank to 48" to take advantage of the plywood sheet size, but that would have meant to cut the glass panels, and I figured some additional length to build filter compartments into the tank itself would be cool too. Basically I ended up with two tanks, each of them LxWxH 60x22x24", resulting in two stacked 135gal tanks.
My collection of woodworking tools is fairly basic... We will need a drill or two with a selection of drill bits, a circular saw, some clamps, measuring tape, and a square. I also own a table saw which isn't necessary, but comes in handy sometimes. I often jump on super cheap deals at Harbor Freight, and my collection now includes cheapo jig saw, finishing sander, and grinder/cutoff wheel. And a rotary tool for different purposes.
Financially, I don't think this will save a lot of money over buying an off the shelf glass tank, especially when counting the hours that go into the project. I don't count them, because this is a fun/spare time project for me. Plywood gives us flexibility with regards to the size and plumbing which gives it an advantage over store bought tanks. And if it holds without leaking, there will be a large confidence boost... hey, I made this! Of course that can go the other way too.
One thing to consider... if not in a hurry, expenses come gradually, which is easier to swallow than one big lump sum. I bought the Epoxy months ago, the plywood over time, usually it didn't cost more than $60 a pop. Having the glass was a large saving for me. 2x4's and wood glue are very cheap items, and over several months I looked for deals that helped me to keep all of this fairly inexpensive.