Pretty much any of them are designed to increase airflow, and quite significantly! I prefer the AFE and Airaid brands just because they have more layers (if your wanting to go oiled) and they also offer the dry filter design as well....not to say they are the ONLY brands to offer dry filters!! Personally have had MANY bad experiences with k&n, lots of fine dust getting through (and this was with a brand new out of the box pre-oiled filter, not cleaned and oiled incorrectly)
More air in, means more air OUT.....don't forget to free up the exhaust too!!
I saw no difference on my '06 hemi with or without a CAI,.. all I got was more noise. Noticed more with an exhaust and superchips tuner and leaving the truck the stock height and wheels