You'll need to be a bit more specific about the types of corals you plan to feed. Most soft corals do not accept direct feeding, and will do just fine without dedicated feeding. Most LPS will benefit from direct feeding, and will generally accept small bits of meaty food, like mysis, Cyclopeeze, and even finely chopped bits of fish or shrimp. The food size you go for depends on the type of coral, though. SPS, on the other hand, need to be fed very small food in the microscopic or near microscopic range. Things like oyster eggs, newly hatched brine shrimp or rotifers are usually acceptable.
Lastly, since you mentioned it, I'd probably stay away from Marine Snow. If the product actually is marine snow, that stuff is already in your tank. Even if it is something beneficial, that product is almost entirely water, and just doesn't seem worth the money to me.