meh, sorry, only dealt with GNOME and KDE. http://xfce-look.org/
here's the best guess.
or you could use metacity. XFCE should be compatiable with that.
many good themes ie. mac for linux, windows for linux, come form there.
edit moar:
the dock is awm.
I suppose you can use cairo-dock and use the fake transparent. xfce doesn't support composting.
the icon theme is any color you like (acyl). should be on the site
the taskbar is just transparent. use tint2 for xfce, much better looking.
and i use elementary theme for the window border, control, etc.