Putting personal preference, aside for a moment, and looking at gas exchange:
Surface area is what is needed, yes, but for gas exchange is is the width to depth ratio that counts. Basically a tank that has a width that is = or > than the depth is going to "breath" better than a tank where the width is < the depth. This is independent of the length. A tank that is 72" x 18" x 24" is not going to breath much better than a tank that is 48" x 18" x 24". But a 120 (48 x 24 x 24) will breath better than either. This has been very long term concept, directly related to marine systems. Why do they still make tall skinny tanks? It is because the bulk of the aquarium trade is still freshwater tanks, by a considerable margin. Generally, and excluding true "cube" tanks (all dimensions equal) for smaller tanks, you don't get a "good" one till a 40 or 50 breeder, and then it skips to the 120, 150, 180, 240. A 175 bow front is a nice tank, but it don't breath worth snot

The "best" marine tanks are always going to be wide (front to back) and relatively shallow.
Jim