For a PC 627 UDR I use the Galco Combat Master. Rides high, but not so high you're hitting your armpit to draw. An even higher option is the Galco Silhouette High Ride pictured on page one of this thread. A DeSantis Thumb Break is a bit lower than the Combat Master, but will conceal under any light jacket and some shirts worn out, but in my opinion, you give up quite a bit of quality with the DeSantis when compared to the Galco.

Pics at Doug Wever's Photo Galleries at pbase.com