i would take a good look at the schwartz headers, they look realy good, they fit T-4 turbos and haev provisions for external wastegate..
http://www.schwartzperformance.com/products.htm and they are almost half price of a banks setup, and im not sure the banks setup is twice as good..
there si also a company called
http://www.ssautochrome.com/level.itml/icOid/1354 that make some tubular stainless ones that cost 350.. but i havent seen them with my bare hands so i really cant comment but i guess you get what you pay for...
fi you do decide to get a set of ssautochrome ones, please post plenty of pics and tell us what you think