Well if you are thinking of any kind of puffer, definitely go light. Speaking from experience here, using a clean up crew as an alternate source of food gets expensive. My mantis just ate $20 of hermits in 3 days...
I'd say go with the cheapest snails and hermits you can. What's the point of buying a $4 blue knuckle hermit when a $1.50 assorted will do? (local to me prices).
Chris