I have had a 66 gallon Malawi setup for several years. Cover is provided by a bunch of river rocks, some slate pieces and a couple of artifical logs/caves that a friend gave me (looks like it was most likely purchased from a LFS). All my rocks I got from a local landscaping supply place. Compared to the lfs, the rocks were really cheap there. My substrate consists of plain old aquarium gravel I had sitting around. I have some plastic plants buried in the gravel. Every now and then I find that they've been uprooted and need to be re-"planted". I used to have floating plants in the tank for nitrate reduction, but over time they seemed to have reduced in population. I'm not sure if they were dying, or being eaten. So I removed them all, and stuck with my weekly 30-40% water change.
I have had my cichlids breed on occassion, but the fry were usually eaten before they could get big enough, although I have two that have survived for at least 6 months now. I've found that my cichlids are quite shy and run for cover everytime someone is in the room. Since my house doesn't have a lot of traffic, I don't know if they aren't used to people, or if they're just naturally shy. Tap water in Edmonton is hard as rocks, so its perfect for these cichlids. My tank consists of 4 adult mbunas and 2 smaller ones.
When you're aquascaping your tank, make sure the rocks are placed firmly on the bottom of your tank before you put in substrate. I've found that my malawi cichlids do dig, and I've had my share of landslides... thankfully with no injuries. Lots of filtration is nice too. I have 2 AC300s and a Fluval404 running on my tank... some people have called me nuts, but if I could add more filtration I would, except my hood won't allow it
HTH
-Richer