Using a Focus cooler has been discussed before. You might be the second one that has done it. I know of a few others that were suppose to do it, but never got back with me about the install details. Congrats on getting it done. I would like to hear if there were any problems or things that you had problems with.

As for using the fuel filters for an in-line filter, I would be very careful about that. As an example, a Contours fuel filter was designed to withstand constant pressure of around 45psi @ idle and upwards of 60psi @ WOT. If you have the filter placed before the cooler, it would have to withstand pressure upwards of 110psi. After the cooler, you are probably looking at anywhere from 0-90psi. So, just a warning.