Brichari are great fish. With 6, you'll most likely get a pair, perhaps two pairs, but I'm pretty sure only 1 pair will work out in your tank (don't worry, when they have little ones they form a colony and your tank will slowly fill up).
Temp. about 76, pH 7.8-8.5, GH/KH as hard as possible. However, despite those numbers, they are rather adaptable.
Tank set up with sand/crushed coral substrate, rocks with caves, no to few plants (they come from rocky areas with little vegetation). Unless your water is high pH and hard naturally, stay away from driftwood since it lowers pH.
Like I said, they're cool fish. The National Aquarium in Baltimore has a large colony and that's what first got me interested in Tanganyikans.
Eric