ebay item #110017966023
it's $160 with free shipping.
it has the correct firing order.
it has a corresponding motor.
Now it's simply a question of how the header-back system will work. With the right ammount of money it looks like it could work.
you could use this same year escort flex pipe (ebay item #170018764194) as a donor for the one escort flange you need.
So let's see-
Donor Flange- $50 (either get the flex from ebay or go to a junk yard and rip one, this is a highball esitimate)
Vibrant Hi-Flow Cat- $70
Universal Flex pipe (2.5" diameter)- $50
Welding- $200 (my best guess could be less or more)
Total is $530 (plus the "cat-back" of your choice)
Seems a little pricey, but probly worth it. I'll see what happens after the holiday season I'll have enough to try it out with my birthday and christmas money.
I still have a Focus parked, I might fix it up one day.