Hi folks, dunno about the sounder advice but I'll give it a shot . . .
Tank is 2.5' long, I started on a similiar sized tank 30"/80cm long, 12"/30cm wide, 15"/45ch high. . . .
Shellies at one end, rock dweller at the other . . .
I think a couple of calvus would work fine, I have never kept them but I am sure I was advised I could keep 1 or 2 in the tank that size. I'm sure you could keep caudopunctatus in your tank, I have seen 6 in a 2 foot tank but been advised a single pair is better.. Tank to tight for Cyps I'm afraid (sorry), been advised 4' minimum, I had 12 in a 4' and felt it was tight, 1 of the 4 males was always pushed away to the upper reaches or behind a rock. I think 3' is minimum for a small group of Paracyps but dunno about the 2.5, again think it would be tight . . .
Here's a couple of cookie cutter examples . . .
• Alto. sp. "Compressiceps Shell"- 1 pair
• 'Lamprologus' caudopunctatus - 1 pair
• 'Lamprologus' similis - 1 trio
• Altolamprologus calvus or compressiceps pair
and one pair/group of:
• 'Lamprologus' (Shellies) brevis, multifasciatus, ocellatus, similis or Neolamprologus signatus
• Julidochromis regani - 1 pair
• Neolamprologus leleupi - 1 pair
• 'Lamprologus' occelatus - 1 trio
Those were for a Rio125, I tink I would have multifasciatus or occelatus at one end with julidochromis dickfeldi or calvus at the other.. I'm sure you could add a third to the mix ... I think kungweensis, caudopunctatus, calvus would make a lovely tank
Hope this helps a bit
Cheers, Sean