Yeah, I'm more and more thinking *not* on PVC.
We have a 28 Ranger, so it's not like we have the room for anything permanently mounted, unless it was a commercial offering in stainless. Ideally, it should come apart or fold up for easy stowage and be as light as possible (which is why I looked away from wood).
Here's a question, how much weight would the boom be able to safely handle? I could just hook the block and tackle up to the end of the boom and swing it over the side of the gunwhale. The heaviest thing we'll be raising and lowering is a deep cycle battery for an electric motor.
If the boom lift is connected near where you connect your load (block and tackle) you should be able to handle a lot but as you swing over the side the force directions change and your boom to mast conection is stressed. Also the lifting halyard may not like being pulled sideways, that being said we used to swing our boom over the side and hang a rope swing for swimming with no problems. I would think a battery lift is no problem either.