Are you talking about $1000 for a custom intercooler mounting job? I'm not aware of any aftermarket solutions.
I'm in the same boat - about to put on an S-trim. There's a thread on here that someone kindly posted pictures of his custom intercooler setup w/ his S-trim - it looked great.
The owner of the local Mustang speed shop who does a good deal of supercharger installs and tuning told me that it's not a matter of IF the meth will clog but WHEN. He still used the systems but said you just had to be sure to regularly maintain it.
I *personally* would go the custom intercooler route. I went with a supercharger over nitrous because I wanted a "maintenance-free" system - the meth is just one more thing I have to worry about - especially since I DD my car.
That being said however, I love Snow Performanance's safeguards built into their system - if my car was more race-oriented I very well may be looking seriously into their solution.
Wes
Wes