Oh there are plenty of woods here that would have sufficed if I was just worried about potential for rot. There is a wood here called 'Ironwood' that you cannot drive a nail thru... you have to pre-drill it for fasteners and it is preferred for any construction around water (docks, decks, etc.). Extremely heavy/dense though. Sinks like a rock.
The problem I ran into with local woods is finding a piece of the dimensions I needed that was clear of knots and/or straight grained. And there is very little need for aged/dry wood here so if I did find a clear enough piece it would likely be green.
As forested as Guatemala is, due to over-harvesting & deforestation (for banana/rubber/palm oil plantations, etc.) decent wood is very hard to come by and/or expensive anymore. Especially anything of any size.
While I would have preferred I didn't have to take the path I had to take I don't regret it. Just one of the prices I have to pay in order to live in paradise :)