[quote author=AdInfinitum link=topic=3373.msg28526#msg28526 date=1351135261]
The 30-36\" depth (front to back) is a given...although if it's going to be against the wall, at 24 tall and 36 deep the back bottom is going to be a long way away if you needed to reach something, unless it's only 4' long (if you 're sticking to the 200 gal range) and you can go from the sides.
Semi coast to coast, ideally teeth machined into the top edge of the back panel 1/2 the length of the tank, centered (quieter due to lower flow at any given point allowing the water to run into the box rather than falling, a sloped panel can be added in the box as well) + BeAn system in an external box (well worth the few inches of extra room space...IMO)
Having had many glass tanks and two acrylic tanks (well one and a project), if money is no object

, I would always go acrylic for a large tank especially if you are using LEDs not halides and/or if you want to put it somewhere awkward to get to in your house. Contrary to popular belief, they are easier to keep clean than glass because nothing, not even coralline can bond to it or etch into the surface like on glass. If/when you do scratch it (they all get scratched eventually) it is easily buffed out even with water in it. Also, over the years my 200 gal has endured a number of major impacts (kids, buddy's with a few too many in their systems and golf clubs in their hands...) and they have all been \"no big deal\" and buff it out.
Anyway glass or acrylic...
Black or dark smoked back panel.
If it's glass euro-bracing (rimmed or rimless), unfortunately not an option with acrylic since the center brace is so key...but no salt creep in the corners, crank up the wavebox without worries, no brace blocking light right in the middle of the tank and always covered in salt and calcium.