The Australian lingo is confusing us Americans . Anyways, you have a lot of options with that 90! Personally I would find out which lake you like the fish from the most, and go with a locality tank. You'll get to see as much of the natural behavior as possible if you do that, and I think that's what makes it worth it .
Is this a venustus? and the Cyrtocara moori in the back ground. Above is my 90 gal mainly malawi tank.I have decided to try a mix of peacocks, mbuna and haps.