dunno about EAC yet, but foobar definitely works with vista... plugins are another story though and you would need to try each individual plugin yourself to be certain.
I'm happy with my vista system now after a couple of months of *cough* fun *cough* with drivers, patches and general microsoft crazyness (eg my microsoft internet keyboard pro DOES NOT work with vista at all!!!) but a crappy old first gen usb logitech clone work flawlessly....