Before ordering this species (if it were me), I would either test my tap water, or.....log on to your cities EPA drinking water report to find out the parameters of your tap water.
I have also wanted this species but because my water in Milwaukee was pH 7.8, and moderately hard (250ppm) I avoided it.
Or here where I live now pH above 8. (even rain has a pH of 8.2 here)
I have seen some research they will do OK with pH as high as 6, but above that, and if its moderately hard, they don't show the same dynamic colors as they would in soft acidic water.
A 40 gal breeder could be useable for a pair, and maybe some surface swimming dithers, but they are after all cichlids, and whether small or large, territorial.
They are no less aggressive than a dovii, in a limited footprint environment
So any other substrate hugger, will be subject to the pairs territorial aggression instinct.
And if you do order, I would set up the tank enough ahead of time, to plant heavily, get the plants established, and add some wood to help add tannins, tint the water slightly tea colored.
These are not "in"expensive species, and while I like to start with at least half dozen of any cichlid species to assure compatibility, a half dozen might run somewhere between $400 and $500.
I know at Aquaticlarity has the listed at $75 each, but because I've known Jeff for a couple decades, and know the quality of his stock, and service he provides...well..