Personally, I avoid recovery moves since we have access to healing items that do a better job. But to answer your question, while either set is fine, the defensive set for Clefable is what I would use. The setup potential with Clefable is amazing w/ Stored Power+Moonblast+Flamethrower in place of Moonlight.
And for Serp, both options are fine. I'm probably gonna run Leech Seed on mine.