Very recently, a new putative Pelvicachromis species from Guinea made its way into the US. Although very little is known about it, what is currently known about 'Pelvicachromis' sp. "Blue Fin" may be found here...
Keeping them in hard, alkaline water may not be much of an issue. Depends upon how hard and alkaline. I would not keep them in parameters equal to the rift lakes. Breeding them and raising the fry would need softer water.
Now it is described in a new gender, it appears that Randall was right to call them 'Pelvicachromis'
A few pics of my Enigmatochromis lucanusi :
It's really a nice fish to maintain and breed. It is important to keep in it aquarium in the long term, considering that he is thought to be endemic of a little creek near a mine, and all the more as there is some political trouble in Guinea.