Hi Snuff -- Well, Occelatus are loads of fun to watch. You're wife will agree once she see's em in action! I have a video of some occelatus behavior--give me your email address and I'll send it to you.
I feed them frozen brine shrimp and crushed dried shrimp, and sometimes some veggie flakes. --but they prefer the shrimp.
Any large mouthed shell works fine --the better ones are lightweight so the fish can move them around--yes, they actually put their shells where they want them---it's amazing! I only have one shell for each fish -- they chose which ones they liked and loyally stuck to them. The other shells were always ignored, so I took them out today when I cleaned the tank.
My 12 gallon is too small for other Tanganyikan fish so after much deliberation and exasperation I gave up and put in zebra danios which seem to be thriving even though the water is set up more like a rift lake's chemistry.
It also makes for an active tank.
If you've got the tank for 'em I highly reccomend them!