Despite the specter of severe AW withdrawal symptoms during any move-related downtime, I think it's likely everyone will support whatever decision you make, Robert.
While I managed multiple corporate file servers for 15 years, and almost always found a way to upgrade them, move them to new hardware, etc, with a minimum of downtime, I realize it's a daunting task and I can't imagine the vastly increased complexity of moving an internet server, with many thousands of remote connections as well as integration onto the Web to worry about. I think you're a step ahead of the game since you wrote all this software so you know that end probably like the back of your hand, versus having to try to second guess the design intent of the developer of a commercial message board package.
Good luck whatever decision you make, Robert!