Thanks for all of the replies!
From what I'm gathering, there really isn't a significant advantage one way or the other, other than the purchased "quick fix" versus the DIY "labor of love".
I have determined that the dimensions will most likely be 72"x24"x36" which should provide a nice depth to the viewing area and roughly 270 gallons.
I'm approximating a cost of $300-$350 for the tank which I think is substantially less than a custom glass tank shipped to my house.
~Eric