Welcome to the forums and enjoy your mod bug "trip".
If money is not a factor, I honestly would suggest getting it all done in one go, however expect to spend around 12-15k.
I suggest you have a read through the 400kw section to get a better understanding of what others have done to get to those levels.
http://www.fordxr6turbo.com/forum/forum/121-blow-off-valve-workshop/
Each time you get a tune done, there is a cost for labour as well.
I couldnt afford to pay what I have paid over 3 years in one hit, so you are lucky that money is not a factor.
In regards to which brand to go with, everyone can make suggestions or say this brand is better than that brand.
However just remember one thing. You are making the final decision.
In regards to intercoolers, everyo e is raving about the johny tig coolers. Have a search for that.
Before you dive into the deep end, may I suggest one thing?
Please do your suspension and brake upgrade before you do any power mods.
The reason we call them barges is due to the stock suspension. Change it to an aftermarket option and you will be smilling from ear to ear.