Before you do it you may want to contact the Fife brothers in southern AZ . They are speakers at many reptile shows they have wrote many turtles and torts .
Download the forms, and apply, best to have a "pending" purchase. The seller can help you sort out the forms and what to say. http://www.fws.gov/endangered/permits/faq.html to start. It's more intimidating than difficult.
Does anyone know of someone getting a permit after Mike Carpenter retired? I got mine just before his retirement, even though I didn't really need/want it, with the understanding that obtaining the permit might/would get much tougher.