Carbon and higher flow. I wouldn't ever frag them and put a slimy one back in the tank though. My yellow leather is as big as a dinner plate in my 260 and it's only a year old. When they get happy they grow like crazy, so you may want to consider only one type. When it folds out it takes up a lot of real estate. The bright colored leathers are going to appreciate being near the top and with high flow for the best display colors and polyp extension. Low flow, less extension. Too low lighting and they get a dirty, drab appearance.
Neon green nepthea and sinularia are sweet. Rival some of the flashy SPS in my opinion. Glow under the right lighting. Ricodea florida and yuma can also add a really nice effect with the right colors.