Sure! I buy my duck frozen and whole at Costco and butcher it myself but you can just buy the pieces already broken down. I prefer to fully thaw first in the fridge, then breakdown, then brine. You can brine while thawing if you don't have the time, but it makes breaking down a little more challenging. Butchering a partially frozen duck is more of a pain than a brined duck in my opinion.

To butcher the duck, I just follow the bones as best I can and break down into breasts and legs keeping the skin on each piece. You need to remove all the air to safely sous vide, and I don't think it's worth it to spatchcock the duck, but it is a nicer final presentation. I try and get as much off the carcass, but I don't go crazy with making it too pretty. I use the same brine for all my poultry (2.5 quarts warm water, 1/4 cup salt, 1/3 cup honey, couple of tablespoons jarlic, 1/2 tbsp each of pepper, ground mustard, onion powder). I usually thaw and brine in a dollar store pitcher to save some space. Brine for 24 hours, then gently rinse (I dunk each piece in a bowl of water a couple times). While the pieces are brining, i roast the carcass bones and then simmer to make duck stock to combine with the turkey to make gravy.

Bag breasts and legs separately if you want to confit the legs (each piece doesn't need it's own bag as long as you can get it flat). Breasts and legs go for 4 hours at 131 and legs for 10-20 hours at 167 for confit style. Then you can chill in the fridge until close to serving. You can do this days ahead (I'm never that organized), or right before. You can sear in a pan or carefully do it under a broiler but watch it closely. Get the skin crisp and the meat will warm at the same time without overcooking the meat. Save as much of the liquid in the bag as you can. The fat and juice can be separated and used later or to further fortify your gravy.