The quiltsmart Double wedding ring does work nicely. I have made several and they come out well. If I were not using that product, I would certainly go for the pre-cut double wedding ring. The accucut pre-cuts are fantastic. they fit beautifully and are all notched so you know just where everything is supposed to go. I'm doing one now with a curved piecing foot and I don't pin anything.
There are also love rings (also a quiltsmart pattern).
I have also asked the bride what pattern she prefers and that is a help. They sometimes like something else. Maybe piecing around an applique medallion, if that is in your reportoire. Congrats! So happy for you!