If you haven't already, start looking at your options for an exhaust,intake and header. If you plan on a serious build make sure you've got good intake/exhaust flow. A happy engine is a breathing engine.
My I/H/E set up as follows:
Cosworth or F2 Intake (Custom one on right now)
Header??? Maybe a Cosworth w/flex, or Marcy's
F2 and Cosworth CAI allow you to remove a MAF sleeve to flow more air. The Borla exhaust sounds great and is 2 1/2" diameter. The header issue is the hardest to figure out. I have yet to decide what size the primaries should be for a NA build.
Read everything you can... there is lots of info on here and alot of Jetters to help you out!
Magnaflow makes a good exhaust too. Its on my 2.0, and sounds great as well. Borla is a little better, but the price difference is pretty high. So depending on how much money you want to spend either are good, but Damage is right Borla does make the best.
But heres my 2 cents. Once you get all that has been stated, have SCT make a custom flash for all that you have set up. You can always change it later.
get ready to spend some money
MM's parts without the motor and no install was 6K for parts alone.
I am waiting to see how much a FI kit will cost but if they will be like the kits for the zetec, they will be 3-4K. I cant see me putting that into my focus!! IMO
Thats Bike or mustang money