Surfing and Whitewater kayaking tripin Central America

Hello I am trying to plan a 4 week trip to somewhere in Central America in January 2014. I kayak as well so I am trying to get on some white water and waves while on the trip. I probably will not bring a board due to the fact of to much gear….? Would that be an issue or are boards easy to rent? Any info on where the best waves are that time of year? I am a beginner/intermediate surfer so I am not looking for gnarly breaks on coral and that sort. If you have any whitewater knowledge as well it is welcomed, really any help is welcome. Thanks