hey grant. For area shadows to render properly u need to tweak its properties (pass1 pass2, blur, etc) in the "Area Shadows Properties". Look up the Viz 4 Help for Area Shadows; it's very well explained with examples.
As for IES files, there are a lot of manufacterers that offer IES files and Fixtures on the net. U can look fo
www.erco.com www.ledalite.com and others like Zumbotel (forgot the URL), etc
Good luck