Do you have wall space up high? You might have to use a ladder to get the frames down but if you had a shelf close to the ceiling they would be out of your way.
Making a strong right angle joint from wood is all but impossible, only metal works for that.I was at Hobby Lobby this afternoon and they stored their empty frames just like my drawing on display panels. Frames are very light weight and needs no additional support if the dowel or pipe is stuck in a wall stud.
just how many frames are you talking about? and the average size.
If in the garage, the studs will be exposed, so easy to center and drill them, not so if in the house, they will be drywalled over.Is the room you are using in the home or in the garage? how tall is the ceiling ?