I don't have plans for you, but I recently finished my own first attempt - literally just cut HT 2x12 dimensions in half and went at it. Nothing fancy, no dovetail, etc - just screws and dowels, and screws and wood glue for the supports. 3/4 Baltic birch from home depot, hardware from amprepairparts.com. All in under $100. My buddy who helped me and I are in the wine biz, so we gave ourselves a little nod on the back panels.
Not fancy and perfectly to spec, but looks pretty good and most importantly sounds fantastic. I tried to upload photo, not sure if it worked or not. Good luck!