um, i dont think id add any of the cichlids to that tank. maybe the firemouths, but definetly NOT the cons. theyd kill everything. maybe if the barbs were kept in a school, like the should be..., because ive herd of danios and cons in small tanks, but still. Id say no to either.
if you really want some NW's go with rams. but not a pair, just two unsexed rams. Or you can do kribs, if you like africans.