need recs for duck gumbo

This Saturday I am planning to make a pot of gumbo with some ducks I have in the freezer. They were picked and frozen whole. My original plans were to boil them with celery and onion and carrots to make a stock, then debone and use the stock after making the roux, the basic normal process.

I've been reading posts lately about roasting the bones. Would roasting the bones a while and adding them back to the stock be a good idea? Should I roast the veggies then boil with the ducks, or not roast them, or roast them with the bones and then add to the stock?

thanks for any advice.