I would suggest making a full size mock up out or cardboard (including the neck) or something else stiff, just so you can hold it up w/ a strap & sit down w/ it & see if those horns are going to be comfortable, or if they're going to be stabbing you. I know that was one of the problems w/ the B.C. Rich Seagulls.
If you're making a mock up, going to make you choose the angle your neck sits at in relation to the body (essentially your body's centerline) & how for into the body your neck sits, which is going to determine your bridge & pickup position.
If it were me, those would be my first couple steps.