Filling feathers for pillows are relatively cheap. You might want to check Amazon or Michaels, or even an upholstery supply. While I have never done anything exactly like this I would think there are a couple few things to be cautious about.
1. Make sure no one in your cast is allergic to feathers.
2. Before using on
stage I'd figure out a way to blow them out in the shop or somewhere to get all the little scraps/ fluffy down pieces out of the pile those floating around could wind up in somebodies nose of down their throat and start a coughing or sneezing fit.
3. However you blow the feathers onstage you need to make sure you blow them across or not too violently, you don't want them going up into the lights; you do NOT want feathers in your lights! I would not try to
drop them from a
snow cradle.
4. My immediate thought is to use something like a large fan on low and have someone feed them in from behind this might require modifying the
screen a
bit so it would require an added amount of caution.
5. Do not re-use them! Use them for one performance then
throw them away or put them in compost. A very common mistake, often made by school and places with lower budgets is to sweep up fake snow, or rice (for rain), or flower petals (for flower petals) and reuse them to save money. Unless you develop an extremely rigorous way to clean those items every night, you run the risk of dust, grit or pigeon poor winding up in someone's eye, mouth, nose, or hair (OMG NOT the Hair!).
Ok, that's my $.02 (keyboards used to have a 'Cents' key and I really miss it.)