well first off..how deep you thinking about going? I dont think the PC3 is built that water proof. And the TT Vapor prob will not get that far also.
what i was thinking was kinda like Oz was thinking..but run the hose behind the quad/rider. your body can prob block alot of incoming mud/water/mooses.
Having the airbox cut on the side is good because you dont want any water/mud/elk to fall directly on the airfilter. putting a splatter shield on Incoming air will work also help. then a one way drain on the botom that can handle the job better then the stock one.
In alaska you should not have a shortage of Jeepers that have built stuff like that.
<---- Im a Jeeper myself.