18 inches in height should be ok and get as big a tank footprint as you can, if your going for five feet length get 24 inch width as well. Ive got a tank this size with a 15 inch longibarbis catfish in it.
sizors;2221281; said:craigslist for the win. you might have to wait for the right one, but it will be cheaper for sure, and most of the time people throw in the extras
12 Volt Man;2224441; said:both Aqueon (All-glass) and Marineland (Perfecto) make the 150 gallon 6 footer.
your LFS should be able to order one in for you no problem.