The command key (cloverleaf or Apple symbols) should work as the Windows key, and option will work as alt. These aren't in the positions a Windows user expects (Win and Alt need to be swapped), but it'll work. Clear (on the numpad) might work as numlock (or might not; I can't remember). Delete (in the backspace position) will work as backspace, and forward delete (in the delete position) as delete. The fkeys should work, with F13-F15 working as print screen, scroll lock, and pause/break. Older Mac keyboards have a help key above fwd del, which will work as insert.
Looking at that particular keyboard, F15 is missing so you won't have pause/break and you probably won't have insert since fn is in that position. There is a key where the Menu key would be on a PC keyboard, but I don't know what it does.
Personally, unless you are using Mac OS almost all of the time, I'd buy the standard version. It'll work fine on a Mac, unless they're doing something stupid. (hold F12 for eject; print screen, scroll lk, and pause/break become F13-F15; num lock becomes clear; insert does nothing useful and menu does nothing at all; windows becomes command and alt becomes option (but again, in the wrong order; they can easily be swapped in Sys Prefs -> Keyboard -> Modifier Keys))
