welcome to the forum, Bridger. I would use an oil based stain, I'm not to keen on water based stains for something that large. I think the oil based stain will give you a longer working time than the water based. Also check over your plywood real good for scratches before you buy it. The stain will bring out any scratches, be very careful sanding the veneer is very very thin. I found out the hard way last week end. Post some pics as you progress and let us know how it's going.
A person can never have too many tools!