Just do a search for "duck call parts suppliers", you'll find plenty! Probably too many.
Single reed calls are more forgiving, but double typically sound better(hard to judge 'sound', too hard to ask a duck which sound better with a load of steel shot in their backside).
Echo is a good one. You can buy the inserts there. Other than that you need a 5/8" bit, I use twist but I think many use forstner. A mandrel to hold the blank too, I got mine from Rick Herrell on here and it works great.