I have always had excellent luck with Galco Gunleather, and while the prices might be a little high compared to some I think they are fair and the equipment is excellent and nearly impossible to wear out.
DeSantis, Mitch Rosen, Don Hume, and Bianchi also all make some nice leather gear.
The Jackass and Miami Classic are both excellent shoulder holsters from Galco, but it appears at this time they only offer the Miami Classic for your XD. The magazine carrier does help balance the ride of the holster, especially for the larger frame (heavier) guns.
While the Galco NSA2 and the Scout are my choice for IWB, it appears they are also not available for the XD. Of the option available, the Summer Comfort would be my choice.
