Good luck with finding a name you're both happy with. I know it's going to be something Catherine and I will have to work through shortly too.
I do like the idea of 'not a top 20 popular name', and 'not totally made up'. I'm also not a fan of strange spellings of common names, as the kid will live a life of correcting the spelling of their name. Not that it stops confusion between long term existing variations of the same name (Catherine/Katherine/etc)...
Any unisex suggestions I come up with are likely in the current top 50, like Cameron, so I'll just wish you luck at deciding on something