Many thanks to you and everyone else who has responded in such an encouraging fashion.
As far as the hardest dance to learn, we've only worked on the salsa and foxtrot to date. Although the salsa looks harder, the basic steps were easier to master. Being slower, the foxtrot appears simpler but requires much more attention to detail.
In any case, we've been having a wonderful time taking the lessons and can highly recommend the experience to anyone interested.
Thanks again to all.