Just look for a hobby shop or place that sells fabric. I get mine at a place called Joanne's Fabric. Most sell everything from leather or vinyl to felt in various colors. They also sell the braided rope that goes around the antler. That way you have a few different options for your personal preference.
As far as the European mounts are concerned, there are a couple different ways to do that too. You can boil them out and touch up the antlers with paint, or you can put them in a plastic bag and set them outside to let the bugs clean them up. If the skull happens to get discolored, you can mask off the antlers and hit them with some flat white spray paint.
Once you get to this point you can put them on a plaque like redrider (very cool by the way,) or just drill a hole in the skull and place them directly on the wall. Another thing you can do is take a boning saw and flatten the back/under side. If you get it a bit uneven when you cut through it, just hit it with a belt sander to even it out. Then, you just put a picture frame hanger on it (the screw on kind works the best.)
I'll post some pics here to show folks what I'm talking about to explain it a bit better.