Depends on the cichlids. Most would be too aggressive but smaller angel fish could work (assuming you believe the "if they grow up with smaller fish they won't eat them" line) but require a tank that is 3 foot long by 18" high as minimum. Kribensis are, IMO, too aggressive for the guppies. Bolivian rams may work, as might apistos (although they could well be too tempted to nibble the guppies tails). Shelldwellers are a nice, small cichlids but I'm not sure how community compatible they are.
Almost any of the larger cichlids are going to be too aggressive for small fish.
With regards to kribs - a lot of people will suggest them so here is my experience. I have 5 kribs, two pairs and a single female. One pair is in a community tank with swordtails, catfish, a panchax and an apisto. The apisto at 1.5 inches (baby) is the smallest fish in the tank. Everyone else is 2.5-4 inches. The kribs behave fairly well - the male chases everything but no-one gets damaged. In my other community tank, with the lone female, I have shredded fins, stressed fish and general mayhem. She is a TOTAL bully and has even hospitalized my favourite cory cat. My female bettas fins are torn to pieces and the other corys and neons are all being nipped.
Just sayin'.