Do yourself a favor and go with [link=http://www.etoarmour.com/]ETO Armor[/link] for all your tank needs. Fast shipping and things ARE in stock.

They have early and late Tiger I tracks from IMPACT to choose from (depending on what version TI you're building) and no, you don't have to upgrade anything when going to metal tracks, but it certainly would help. Ask Bob what's needed when you place an inquiry on your order and he can let you know what's available and what you can get by with just starting out.

Hope this helped some!