Yeah, I'd say if you're going to upgrade the turbo or not. The TMIC is probably more benefit for your buck. Now, if you get the PnP manifolds it won't hurt but its more beneficial if you're actually thinking of upgrading the turbo. Because you will be looking to squeeze out a little more power with the manifolds. Mean while...the larger TMIC if its quality part will cool the charged air better, have minimal pressure drop, and a larger area to cool more air over the smaller IC. All good things with a tune because it will allow you to turn up the boost/timing more because the cooler air lowers the possibility of knock.
378awhp/373wtq Custom Dom 3 & CBRD tuned 2006 STI.
"When in doubt...flat out" - Colin McRae