Go with the 4X4 since you snowboard your going to want to drive thru the pow when it comes and since you surf you may find a beach where you can drive and clain your own stake at a point and your gona want 4X4 for that as well. The neoprean (wetsuit material) are seat covers for the xterra i dont have them yet but iam planing on getting them, you might also want to consider the rubber flormats. DaKine makes some nice roof pad systems for surfboards. Also just go with the aftermarket sound system nissans dont come with good sound systems and from what i hear the rockford isnt as great as it looks.