I would use wood primer, followed by undercoat, then gloss paint.
Is it for outdoors or in? I have something outdoors made of plywood, and the best thing I found for that was yacht varnish. Varnish can look good even if it is for wood indoors.
indoors only, Im very tempted to get my mate to print off some vinyl for me and wrap it in that but i still think itd need the undercoat or alot of sanding!