On Amazon or Ebay. Been using them from various vendors for years. No problems other than the one pinout difference, but I've hardly used the analog input pins (other than as digital), or the imitation analog outputs. Here's one vendor I've used on Ebay: The vendor I've used on Amazon appears to have folded his tent. I've also bought Uno and Mega boards that way. I'm a retiree and have to watch my spending. No problems so far. P.S. It's interesting that the Adafruit servo software has no problems with it. Either it's a known and common difference, or they do a search to find the pins which would indicate that variant locations are not unknown.