check Downey and Edelbrock. To my knowledge, they are the only two companies that make a smog legal header for the V6, although I don't know if they offer a legal one for the t100. If legality is not a problem for you, then any of the 3.4 V6 headers should work. There are some others I have seen on ebay that look promising, but aren't legal.
Oh, and there's TRD, but they are spendy. Again, dunno if they have them for the t100. I was just shopping for a 97 4Runner, so ymmv.