Mark,
much will depend on how much of a habitual fiddler you are (or want to be)
For EPR, many of the CAT drivers appear to have settled on the spring combo that your version came with - with possibly the option to drop a rate to Red fronts and yellow rears.
Can't really comment for the Fav indoor surface but for outdoor, I doubt if you will move around much from the standard combo unless you feel the need for a fiddle