I won't be back on my boat until the end of this month but I know that the pulley is just as important as the alternator. You want to make sure that the diameter of the pulley is small enough generate sufficient rpms. Also, the pulley on the propeller shaft of my boat is a multi-V belt, so the pulley on the alternator had to match that. Finding the right pulley for the alternator may be harder to find than the alternator. I'm pretty sure the alternator I have is a Motorola product but I don't have the part number at this time. I can get you the alternator part number and the diameter of the pulley the first week of January if you can wait that long.
I'm not surprised that you could not find this exact alternator in the US. I had the same issue but I was able to have a local alternator shop review the specifications of the alternator I needed and have one made to those specifications. You might want to research that possibility.
