I know Hive.blog and ecency have referral links, so that's doable. I've been looking for nearly a year (since I got to Hive) and haven't found one like this.
Implementation should be fairly easy to program, but it would require a developer some time... based on my limited knowledge of coding, it seems like it should be simple.
As for resources, that's a question I can't answer but would definitely like to see answered, too.
Thank you so much for your contributing comment!