Currently my font stack is
"HelveticaNeue-Light","Helvetica Neue Light","Helvetica Neue",Helvetica,Arial,"Lucida Grande",sans-serif. The issue I'm having is that some of my images/buttons with text are forced to be either HelveticaNeue or Arial - one or the other, obviously. If a user without Helvetica (Windows users) visits, the Arial body text clashes with the HelveticaNeue button text, and then vice versa.
If I use Arial as the first font in the font-stack, will a large portion of Apple users see Arial? Does Arial ship with Apple devices, and if so, when did they start this?