You can find them all the time on E-bay.
What I see most often is the Italeri kit. It was also re-boxed by Revell. It 's a pretty descent kit. It's an old kit but builds out nice w/ some photo-etched parts for the finer details. It does have the rubber band type tracks.
The Dragon kit is a little better - more detail. The flame-thrower version, thundergod mentioned, can be built as the normal version - there is an option w/ the kit
Try this
http://search.ebay.com/hetzer_W0QQsosortpropertyZ1
Good luck