Although most of what the company makes is junk, weapon R makes a very good cold air box for the Rx series.
http://www.eautoworks.com/html/ORD-1-1-1-24286.cfm
You can order it with or without the cold air sheidling (the box part) although for a daily car, the extra outlay is worth it, as it will do an excellent job of keeping the air around the filter cold, and keeping hot engine air away. Some thermal coat on the Aluminium intake pipe is my personal recommendation (as always) to keep the intake pipe from absorbing heat from the engine bay. It wont look to good, but if your buying it for added reliability and performance (and sound, my favorite intake by-product) then it will really help.
You can also get high flow filters
http://www2.lexpartsonline.com/parts...ter&category=B But that wont really do much, other than save you the cost of replacing them vs washing.
Honestly, I would just go to any sport performance shop, and ask them to make you up a better intake pipe if you want one. This would be the easiest way to do it. Just ask them what would be best and they will most likely make you up an ABS plastic shielded pipe made out of ceramic coat aluminium. At least thats what I would do if I wanted to put an intake on a car not often modified.