i did my old 500. just did it myslef with plumbing supplies. you will need 2 snorkels for the intake and 1 for the belt intake and 1 for the belt exhaust. check out High Lifter - The Leader In Custom After-Market ATV Accessories lots of info on doing this yourself on there.
all depends how much you want to spend. i spent 50 bucks and used pvc. my dad tells me it looks like a sewer system. but if you are actually going to use the snorkel, your quad will probably be COVERED in mud and nasty stuff so does the way the snorkel look really matter? i suppose if the bike is brand new maybe i would consider a professional system...just my 2 cents