A few ?s before I buy a Rubicon

Fixing to buy a trx500fa6 but wish it came in green! Is there any reason to buy a 2016 Rubicon when I can get a 2015 cheaper? Were there any issues that had to be worked out from the 2015’s that may be resolved or fixed in a 2016? Is a rear brush guard a good investment? What about a skid plate? I would not be riding over big rocks but would like keeping junk out of the bottom of the unit as I ride on trails, sticks, etc and through shallow water such as creeks and puddles. I also would like a winch. Is that something I can put on myself and where would the mount/controls for it be mounted most likely if I were to do that? Where do most people buy accessories? Amazon?