Oh Sky-O, I'm so sorry to read this news. You have my deepest sympathies on your loss.
I didn't get to post earlier but I hope that you will find a way to memorialize your beloved friends in a way you feel is comfortable. It's not an unusual point of view at all, I've felt the same. (((((((((Hugs)))))))
Late to this thread but just wanted to add my support. Really hope you can settle on a plan that feels right for you and how you feel the bunnies can best be remembered.
Regarding your original question, I am sorry I don't have an answer but it is something that I think about regularly and also feel that it is important.
I hope you are able to find a solution that you are comfortable with x