You should take the Pipercross kit into consideration, it is cheaper than the J1, I recently installed it on my Fiesta, great quality and noticeable improvement both in sound and throttle response, although it takes a little bit more time to install....
I will upload a short video to show how it sounds....
Car looks very nice , your doing some good additions. No so sure you will be able to fit the Ecoboost Engine in there , without most of the wiring loom and modules and power train , i would imagine it would be a very large project to undertake such a task. But if you manage it post a fitting guide i'm sure people would like to see how it turns out.
I know it could be a large project, but where is the fun if it all just bolts on? The only thing that worries me is the electronics, but I have a friend who could make it work
EDIT: I was thinking of a 148 bhp 1.6 ecoboost swap, because it has enough power,and does not require complicated power train modifications
I have thought about doing that modification,but gave up,because:
1.when you close the bonnet,there is absolutely no flow of air to that spot,because the upper grill is fully closed,and there is no air coming between the grill and the bonnet due to rubber bonnet guards taped on the bonnet edge
2.the only way to get any noticable amount of air coming to that spot is to modify the upper grill.....
not much you could do really,i have a 1.25 in my mk7 fiesta,went to see what SKN tuning.de had to offer: +14 bhp and +15nM,not bad for a N/A engine,they also give full warranty for the performance gain (still believe that the increase isnt that much,probably around 8-10)
so that is the first thing that i will do after my warranty expires,than probably a full miltek exhaust etc.
hint: took the car on the dyno run: it puts out 86 bhp (if i remember correctly) instead of 82 bhp ; also it is a standard car,no engine tuning yet