Nope - the jewel is african riverine, but depending on the individual fish they can do ok with rift lake.
Tank looks very nice.
As regards stock, if you keep more than one of a species of mbuna you should keep 1 male and not less than 2 females. 1 male and 1 female will result in the male harassing the female to death. 2 males unless in a very large tank are likely to hammer each other. In a small tank this will be magnified greatly (less than 4 feet length).
I can see difficulties in your future when the cichlids mature - in that size tank they will likely wipe each other/barbs/corys.
Corys are not a good choice for catfish in an african tank at all - too gentle. You need something robust - synodontis multupunctatus, some plecos.
I would move out the corys & barbs, and upgrade to a 55 gallon and stock it with more malawis. I don't think the 30 will be very comfortable for long.
