It's not a 21st century or New Millennium, and it's not labeled as a Pz IV, but it sure looks like an Ausf F or H. There aren't any track skirts, but it does have the external plates around the turret. There are also some side fenders that would have to be cut away.
Here's a couple of the pictures.


and here's a link to the guy's ad.
http://cgi.ebay.com/New-1-18-Radio-Remo ... dZViewItem
It's also not painted correctly and has some bogus decals on it, but it might make a good basis for a re-work.
The guy is asking $43, which includes shipping, so this might be a good alternative to trying to find one of the very expensive European only versions of the Panzer IV , equally rare US versions, or the New Millennium models which seem to only come available in the short barreled Ausf D versions.
Cheers