Don't know if you are still looking or not, here is one in 2 sizes and its free.
I see you have a lot of answers so will just give you a flower!
Here is whatI could find for you with the keyword search of "celtic":
http://www.starbirdstockdesigns.c...
I searched with keyword "claddagh" and found this site with some really nice hearts. (and claddaghs)
CU
Eva
The second link is realy nice, maybe a bit more in the line that you could use.
designsbysick has some nice celtic designs, including a set of hearts. They're a bit big, but you may be able to shrink them.
http://www.designsbysick.com/buyd...
Good luck!
I saw this one yesterday, it's a FSL one ( the first and the last link), finding a free heart was a bit hard but the last link was the cheapest. Maybe you could use the FSL ones to do your own thing. The other links might also help.
I noticed that the LAST date on designs added to this site was Feb. 2005. Have they moved to a new site?? Or stopped altogether??
There is one on Emblibrary site. I will keep looking. A great one on Windstar Embroidery too.
Love and blessings Chris