I would say your best bet would be to go with a KH disc brakes as it's a factory option. Scarebird also provides a pretty cheap kit as well using a wide variety of different parts but you need to do some grinding to get them to fit apparently ( https://scarebird.com/index.php?route=product/product&path=64&product_id=102 ). I believe Wilwoods can be either 5x4 or 5x4.5 but they say it fits "Most 15 inch wheel" with only an 11" rotor (which I'd assume should fit a 14" wheel). Not many options for the stock wheels.