Here's what I had at my old place, a rack which I made myself from pine boards from Home Depot, stained with some minwax stuff.
Well, my rack didn't hold enough guitars. I didn't plan ahead enough, LOL.
Since then I've moved into a new house, and thought to get a similar rack professionally built, as mine was alright, but clearly a bit amateurish. I found some custom furniture makers who, I guess outsource the work to china or indonesia. They sent me some drawing of some pretty cool and elaborately carved designs based on my rack, with pretty reasonable prices (actually, unreasonably low... less than $300.00 ). I kind of dropped the ball, in that there were some details of the drawings that weren't quite right, and trying to fix them via computer was a bit of a PITA, and some other things came up which kind of made me forget about the whole thing for awhile... (need to get back on that project, actually).
The method of attaching this to the wall was as follows: Two 4 inch bolts screwed into wall studs (after predrilling pilot holes -- after much cussing and drilling random small holes in the wall attempting to find the studs). These bolts protrude a good one inch out of the wall, as out of the sides of Frankenstein's monster's skull.
Two half-inch holes drilled in the rack -- big enough to fit over the heads of the protruding bolts. These holes were drilled AFTER the bolts were installed, and after measuring things _very_ carefully so that they holes lined up and
everything would be level. Then the rack is just suspended on the bolts.