the idea is to make it a kit with the least amount of "find it yourself" or "make it fit" kit.
THe easiest thought was, of course, to have a 3->3.5" intake, that would go through a hole cut through the fender, and connect to the stock airbox on top of your carb or TBI.
The options of course, was whether to keep a stock filter setup (TBI style) or to go with a Open cone style. The open cone (with the silicone cover) looked pretty good, it shed water pretty well when I tested it. I dont think it would help save you if your up to your roofline in water, but it will help prevent water from getting through from rain/splashes, etc. THere was also the option of perhaps doing it HUMVEE Style, with the air intake like a mushroom cap, and then having a first layer sponge type filtration.
Im curious to see how ARB deals with Rain issues, as their snorkel is top mounted, facing forward like a scoop.
That being said, there's always the option of using a diverter, since rushing liquid has more momentum than rushing air, the liquid can be forced out at the bend.