Darkpuppet, what are you looking for? I mean, why do you want to have bigger brakes?
I too would be leary of changing the braking system on the Advance Trac cars. Not unless it's really necessary. I just don't see the point on a street car. The risk of upsetting the system just isn't outweighed by the extra braking that you don't even need on the street.
As for the Wilwoods...
I'll have a post season tear down coming up soon, and I'll report any unusual wear I see from running them on the street all summer.
Frankly, they increase the durability of the braking system so much, it would even be worth replacing the calipers yearly for a dual purpose track car. Think about it, new calipers are $150 each.
It's pretty easy to go through 1 set of stock type racing pads in a single trackday on a powerful car. At $100 per set of pads (Mintex, Hawk, whatever) it would only take 3 track days to burn enough pads to pay for yearly Wilwood caliper changes.
Consider that the Wilwood setup is so powerful, that I have no noticable wear on my Wilwood racing pads after 200 miles on track...
The total yearly cost on a tracked car is still lower, even if you have to replace calipers every year, which isn't very likely.
I expect, worst case I'd have to replace the pistons and seal, probably cost $50 or so.
Like I said... total yearly cost of the Wilwoods for a tracked car is going to be lower than constantly burning up expensive stock sized pads. Then factor in the increased performance, safety, and confidence... It's well worth the risk that *Maybe* you'll have to rebuild, or replace the calipers.
As for tapered pad wear, etc...
From what ChrisF and I have seen so far, it's not a factor. I think some people used the Wilwood dynalites and/or superlites on really heavy cars, that stressed the calipers too much, and resulted in un-square pad wear (whether it's tapered, or in the middle, etc..) But on the Focus, with these forged superlites, again, it's not an issue.
And here's something else to think about in comparison to the BAER system:
Talk to the Mustang guys who track the car. They get the brakes so hot, they burn the dust shields off the PBRs anyway! So, I figured, if I'm gonna burn them off anyway, might as well use calipers designed not to need them in the first place!