Same stuff they use for cold air intakes and intercooler piping. Mandrel bent pipe and rubber sleeves. Check out some of the ricer performance shops around town or eBay and you'll find it.
Personally, I would make a fitting to connect it to and some of the IC/CAI piping already has a bung for it. Several people on here have just stuck a filter on the end of the tube coming out of the valve cover. It is part of the pcv system, but it's not the pcv valve. That's under the intake. Because of the way the pcv system works in these cars, I would make the connection at the intake and hook it up right rather than risk a build up of noxious/acidic gasses in my crankcase.And lastly, being a California car, it is equipped with a BCDD, I don't see anyway to reinstall that, so I'm going to toss it, right? (good riddance)
Cap it or put a filter on it.