i had baby two snappers with african cichlids and other fish (125G). The snappers ate everything but the three cichlids. They also tore up all my plants and re-arranged all wood and rocks. I'd say a 100G tank is good enough to house snappers in for about 5 years. But like the others said, dont expect to have much else in there.
Since getting rid of the snappers, I've moved the RES into the 125. There are lots of fish in there now and everyone seems to get along. I have a Silver tipped cat, some school fosh in there, couple loaches and a plec. The African cichlids are doing great, even had about 30 babies since.
Still having problems with the plants tho...