there are a few versions of cf runners, I don't even recall who made the ones I put on my 916, I bought them used. Just be aware there are some cheaply made replicas out there. For the air filters I installed the inside the airbox BMC filters. They cover the airbox to air runner openings securely by way of a bracket for each filter. If you go with them just make sure you position the brackets out of the way of the spring clamps that hold the air runners to the airbox. However, even if you mess that up its not a great loss because the filters do a good job allowing only filtered air in at that point. As you can see my airbox is also cf, but I don't think that matters when installing BMC filters.
Then theres the whole thing about air turbulence and filters. I heard all that, I read negative reports about the over the bellmouth filters. I liked mine, it was a good fit and the filters are easily cleaned. Even if there isn't appreciable gains by the above, the change clearly upgrades the look of the bike and you shed a little weight, especially if you go with the cf airbox also. No question I would do it again for purely cosmetic reasons.