Question regarding Facebook comments

I want to add Facebook comments to my blog, but I also don’t want to loose all the comments from all previous posts. I’ve been reading all the different ways to install Facebook comments, but haven’t found the best way to add them yet that still allows me to keep all the old comments….and also I’d like to be able to allow to allow people who do not have Facebook to comment as well.

Has anyone found any good ways to implement this?

Thanks!