Yeah, I haven't seen any 4e Harn stuff. Personally, I would just go with Michael Cule's 3e Harn conversion. Nothing really needs much changing aside from his system for religious magic though you might find something in Thaumatology that works.
http://www.sjgames.com/gurps/Rolepla...URPS-Harn.html
I ran a Harn game for about 3 years using this as a starting point. The only thing I changed in a big way was the above religious magic. I wanted something a bit more subtle and cribbed from Path Magic, mostly adapting existing rituals to the various gods, making up a few of my own for the two clerical characters and just winging it for NPCs.