I would start by deciding which substrate material looks the best to me. Then I would decide if I am the type who needs the crutch that ADA soil provides for absent minded fertilizing - forgetting to do so many times. If I were that absent mnded I would want the ADA soil, if I liked the color. If not, I would probablly use SMS, accepting that it may depress the KH of the water for awhile. Since you listed only black or dark gray substrates I assume that is what you want. Finally, I would look for a place to buy 3M Color Quartz black sand, to see if it is economical. If so, and if I didn't want the fertile substrate, I would use it, because it is heavier and easier to plant in.

SMS is very light weight, and at least when first added to the tank, it doesn't hold small rooted plants well at all.