If you want to maximize every bit you can out of the car, get whatever downpipe/exhaust and the WGA. The downpipe does add power, Adam even verifies this, just not power where we want it, which I believe is why he does not recommend it, as it causes a loss of power in the higher rev range. That said, those mods are going to cost $1000 or more not to mention labor. HP and TQ gains are minimal from all of this, we're talking maybe a few from the exhaust and actuator each, maybe 15 total. For 15hp I would not spend all that money but to each his own. Without these mods but with a FMIC and intake or panel filter and a custom tune, Adam's tune in this case, you are probably getting >90% out of the stock turbo. I could be wrong there but I am sure that it is definitely a high percentage.
This was my thinking in my mod path. So you spend $400 on Accessport, $300 on FMIC, $50 on a panel filter, and $150 on a Tune+ tune and you have 90% percent of available power increases for $900, install all that yourself very easily. Then you spend another $1000+ plus labor if you can't do it yourself and get that last 10ish% of the possible power out of the stock turbo. For me, the law of diminishing returns stopped short of the WGA and exhaust. With Adam's tune I'm around 220hp/295tq on the V-dyno which means nothing but it does give us something to compare with other V-dyno charts. And I'm in the Georgia heat. My AP has estimated torque at 284 though I have not kept it floored in 4th gear to redline ever. Were I to do that I bet both the AP torque estimates and my V-dyno numbers would exceed what I've listed above.
Anyhow that's my thinking, just my opinion, hope it helps. Either way the custom tune, in this case Adam's tune, is a whole new experience and I highly recommend it. I'm quite happy with my car as it is. Now I just need to figure out how to get a Focus ST steering wheel in my FiST, I experienced one last weekend and no longer like my steering wheel.