Many thanks for the compliments, and sorry for not getting back to this thread for a few days, but I was busy completing the section of my web site about this tank: http://www.fmueller.com/home/aquaristic/125g/
Regarding the camera, I reckon any DSLR will do the job. Mine is a Canon Rebel XT, which of course by now is 'outdated' by several generations
You want a flash unit that you can use off camera. I am not always using it, but you want to have that option! You also want some decent lenses, and I used a 17-85mm IS, 100mm macro, and 50mm 1.8 to shoot the spawning photos. All of the lenses gave me some decent shots. The key to success, however, it to take lots of photos and only show the best. I took 500 from which I selected the above 5!
Regarding food, these are my first tropheus, and while I get a feeling that there is a lot of hype about things that you should not do with tropheus, I do believe that these fish have sensitive stomachs. I bought them with a 5 pound bucket of Xtreme Cichlid Crumble, and that's all they ever get - apart from the plants in my tank that they keep nibbling on!
Dan, I don't think I've ever seen your photos of frontosa males holding eggs! Are they available anywhere online? It sounds like the most curious thing I've heard about in a long time!