Like Paige, ours aren't all that fond of duck either. They'll eat it, but they definitely prefer rabbit. With rabbit being so much leaner, it's a good balance as duck has a lot of fat content. Chicken is third on their list, and I need to be pretty particular about the quality I'm using. Either a drive down to Amish Country, or a trip to Whole Foods. Everything else comes from Hare-Today.
We currently make about 75lbs at a time. It's a big chore but it lasts for a bit and freezing doesn't have a lot of negative effects under 90 days. Cleaning and prep takes about 2/3s of the time, so it isn't a much bigger bigger time commitment to make 75 lbs as compared to 25lbs.
As for storage, we use quart size freezer bags. Easier to store, easier to get the air out of the bags and easier to label. I'd prefer to use something reusable, just too much stacked up against it. Food stays fresher when thawed as we can continue to keep the air out of the bags and they are filled with different quantities as two of our three cats have reduced protein needs.
If you are adding extra bones, I would try to offset it with some organ meat. I also wouldn't exceed 10% of the of the total weight with extra bone. You start running the risk of constipation pretty quickly and might see some ghost poops comprised of not a whole lot more than calcium.
With RDAs it's pretty difficult to discern because there just isn't good data on a lot of the ingredients. Chicken, Rabbit and Duck are easy to find data on, just that it's rough because you are also using the bone and organs.
As a baseline, I use Dr Pierson's recipe for Chicken and then nutritional value from this site for the rest of the data.
http://nutritiondata.self.com/facts/poultry-products/663/2 It enables me to get relatively close and the rest is handled by a varied diet.
Hope that helps!