Brian, it only sounds complicated because we provided you with a plethora of information based on years of experience. It really isnt difficult at all. Just print this post and take it with you to the pet store. It really is easier to maintain a larger tank.
These are the steps to use no matter what size tank you want.
1 Purchase tank, stand, gravel, Stresscoat, Aquarium salt, hoods, lights, filter and cartridges, heater, thermometers, air pumps with airstones and (or) srtips, hoses for them, tank backdrop (picture background) and a net. Ornamentation and plants too, but it isnt necessary right at first.
Note...You can get most of these items in a package depending on where you go. Walmart and Pet Smart have a 55 gallon kit with everything except gravel and the tank's backdrop. The stand is usually sold seperately though. If you want something larger than a 55, you'll likely have to get everything seperately.
A declorinator usually comes with the packages, but I recommend Stresscoat. It is a dechlorinator, but it also is good for the fishes bodies.
Filters- When you buy filters, they usually come with cartridges with them. Each filter box has a number on it. example, 60 or 80 or 120. That number is the number of gallons of water that filter will process each hour. If you get the 72 gallon tank, I would get at least 2 filters that process 100 or more gallons per hour.
Heaters have the amount of water that they can heat printed on the box. I'd recommend a heater with the temperature numbers printed on the thermostat. Just for a point of reference.
Air pumps come in all different sizes. You can get a large one with 2 hose outlets on it. That is 2 lines, but only one plug in a powerstrip.
2 Once you get it home, set the stand and tank up exactly where you want it before you put water in it. Put the backdrop on the outside of the tank. (Allow about 8 inches from a wall so you'll have room for the filters) Then, put the gravel in it. Then, put the hoods and lights on it. They have places in the back of them for filters. Then, put the filters on with the cartridges in them, and fill the filters up with water. Then, plug them in. Then, put the heater and thermometers in. Then, follow the instructions on the Stresscoat bottle and the aquarium salt container.
Let it heat up to 83 degrees, then you are ready for ornaments, plants and fish. I recommend tetras at first.
Once you are ready to add more fish, use this link. It is a compatibility chart.
http://www.liveaquaria.com/general/fwcompatibility_chart.cfm 
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