I don't know what telnet client you have on your mac...
but if you can't get in and look at this directory...
you can pretty safely assume that they should have installed urw-fonts, which are licenced under the GPL to include the 35 standard Type 1 PostScript fonts - which match the original Adobe names - Times, Helvetica, etc.
But it is not as simple as it seems - to use fonts other than PHP's 1-5, read about imageLoadFont() in the manual.