I wouldnt buy that header. 200 bucks is CHEAP for a tubular style, and the quality doesnt look good to me. Ive heard horror stories about all those ebay headers cracking. Have you looked into the SBR exhaust manifold? If i were to get an exhaust mani, that would be it.

Is this going to be your daily driver? With a turbo that big, i would want an external wastegate setup imo. Also, i dont think your motor will last very long if you run that turbo in its efficiency range on a stock block.