There have been a few of us that have had the conversion done by Keith Kearcher. Keith has since retired and his nephew Kody Kearcher has taken over his gunsmithing business.
http://members.toast.net/keithkearcher/
When I had one of my Repros converted the cost at that time (2011) was $300 plus shipping. Here's a link to a thread with more info:
http://parkerguns.org/forums/showthread.php?t=3216