Yes, this would be specifically for mbunas. I am mainly concerned about weight as I cannot see how the flooring was structured in the developed basement. I would assume the wider and deeper the tank the better the distribution of weight. I figure about 1000pounds all in for the water, aquarium, rock, stand and filter. The only downside with a custom 46" tank as I cannot get a 4' tank in there is that I need to be creative with lighting and a cover.
And, yes, I am planning a large rock mound. Just researching hardscapes right now. Thinking 2/3 rocks and 1/3 sand for the bottom. 2/3 of tank height will be the rock mound.