You can put any brand of filter on any CAI/SRI, as long as it fits. Best way to go is to measure the CAI diameter and measure your filter's length, plus diameter at top & bottom. (THe tighter the fit for the filter, the more important that you measure carefully, of course)
K&N's web site has a whole listing of their filters with all of these specs. I would imagine most filter makers, if contacted, can give you a part # to match your measurements. I had an aftermarket CAI on my '05 MINI Cooper S that came with a cheap foam filter. (I hate foam filters) Measured the sucker, looked at the K&N site, found a replacement from an online parts supplier. Problem solved.