Welcome to the forum. The XD45 is a nice firearm. Now you get to enjoy the quest for the perfect holster. I would suggest taking a look at the Crossbreed Supertuck. They are a sponsor of this site and they make an awesome product.
I would suggest one thing: stay away from holsters with a plastic hook on it. I bought one of those cheap Galco holsters with the J-hook, Ultimate Second amendment or something like that; the hook broke off twice. Don't try to cheap out, get something that will last. :biggrin:
Welcome to a wonderful site!!! As far as the holsters go, there are too many, and each one is different per person. Try a few & get the one that works for you. Personally I have had wonderful, comfortable luck with DeSantis. Again, welcome, and good luck!