Hello, fully raw feeder here, going in 2 years.
Just to pitch in a little:
1. Beef bones are not safe for dogs of any size. It's too dense, and can crack dogs' teeth. The most I would give my Mocha and Lulu are pig bones, and not any weight-bearing bones. Baby back ribs, pig feet, pig tails are all superb.
2. By cutting the wings into pieces you are making it unsafe for your dogs. Feed whole pieces - wings, thighs, breasts are awesome.
I get my meat from supermarkets or traditional markets with butchers. I look for sales - sometimes they have promotions on chicken breasts and it will cost less than whole chickens! Since guidelines for raw is 80% meat, 10% bones, 5% liver and 5% other organs, it's a catch!
Just my 2 cents