Damn, I forgot about this thread.
That was my 20gal starter tank in that photo. Only had four juveniles in there at the time. I upgraded to a 55gal about six months after that and added a bunch more fish. These are some old shots of the new tank. I've added some more coral and ornaments since this was taken...
Cichlids are crazy territorial and like to stake their claim to a relatively small area, so putting something in the tank with lots of holes or areas to hide will help keep the fighting to a minimum. Here is what I have in mine now...
One of these in the middle...
Top Fin® Stone Coral with Coral and Plants
Two of these, one on each end...
Top Fin® Coral with Plants Aquarium Ornament
...and one each of these placed in at random...
Top Fin® Stone Cave with Snail Aquarium Decoration
Top Fin® Barrel Aquarium Ornament with Airstone
...and a set of these all around the tank...
Glo Moon Rock Cave
They are burrowers too, so anything you put in the tank needs to be heavy enough that they can't uproot it. They will tunnel under anything you put in there. My new tank has a layer of gravel about 1" thick with a 1" layer of sand on top of that. It's completely self-sustaining. I don't use any sort of under-gravel filter, 'cause those things are a PITA and create more algae than they filter. I just scrape algae off the glass about once every couple weeks, but it never gets that bad. Uneaten food sits on top of the sand and I have a team of Emerald Cory catfish (Brochis splendens) that clean up. Those things are vacuum cleaners and the only thing I've put in the tank that the Cichlids haven't killed. The clown loach in pictured above only lasted a couple weeks. All I found was its head minus the eyeballs. :? Put two synodontis petricola (African pygmy spotted catfish) in there too and they didn't last three days. For some reason, the cichlids completely ignore the Cory cats.
As far as the cichlids, I started off with these...
2x Yellow Labs (Labidochromis caeruleus)
2x Electric Blue Johanni (Melanochromis johannii)
2x Giraffe Hap (Haplochromis Venustus)
2x Kenyi (Maylandia lombardoi)
2x Demasoni (Pseudotropheus demasoni)
2x Lavendar Mbuna "Rusty Cichlid" (Iodotropheus sprengerae)
2x Bumblebee (Pseudotropheus crabro)
2x Snow White (Pseudotropheus socolofi)
2x Cherry Red Zebra (Pseudotropheus estherae)
You can see pics of most of them on the first couple pages of this thread. All of the species listed above are Mbuna cichlids (endemic to Lake Malawi, Africa). Most Mbuna are vegetarians and are algae grazers in the wild. They eat low protein spirulina flake food, so you don't have to worry about feeding them live fish, bloodworms, or anything of that sort. Some are more aggressive than others and all got along pretty well as juvies. Once they reached maturity my tank turned into an all out gladiator academy. They are more aggressive toward fish of the same species/color and the pairs went at it relentlessly. Here's what I have left...
2x Yellow Labs
1x Electric Blue Johanni
1x Giraffe Hap
1x Kenyi
0x Demasoni
2x Lavendar Mbuna "Rusty Cichlid"
1x Bumblebee
1x Snow White
2x Cherry Red Zebra
The less aggressive species stay out of each other's way, but the more rowdy ones didn't stop until one died. The demasoni were my favorite, but they fought so hard that both died from injuries. They all started out about 1" long of just under but now they are all 3-4" long, except for the giraffe hap which is the largest now at about 6". Just make sure when you start out to get them all about the same size. If I had it to do all over again I would have bought a couple pairs of yellow labs and one each of the rest. The yellow labs can get along in groups for some reason.
The other thing to research is setting up your tank before you get the fish. Especially with a new, large tank it could take 2-3 weeks for the water to run the nitrogen and ammonia cycles necessary to sustain the fish. Set it up how you want it with all the sand/gravel and accessories, plug in the filter and light, and then let it sit. The waiting is tough, but well worth it when you're spending a good amount of money on the fish. I tested the water out with a half dozen $.99 zebra danio for a week before buying the cichlids. Filtration is important too. I run a 75-100gal filter on my 55gal tank. It keeps the tank nice and clean while producing a current that the fish love to swim against.
Hope that helps. Let me know if you have any other questions...