Most of the name brand patterns are licensed and you are not going to get licensing to print them unless you are committing to six figures in guaranteed revenue....
So if its a name brand one then you are going to have little choice but to order some already printed from a company licensed to print it. Metro Restyling is licensed for a few brands including Kryptek and will even custom print for you. I know because I've actually ordered it from them for a major client. They will print it on Avery 1005 or 3M 180 with gloss, satin, or matte lam. Some others can be ordered from other suppliers like Fellers has some of the Mossy Oak patterns on 3M.
As far as getting patterns you can print in house, for nicer photo realistic ones there are not a ton of options but Aurora Graphics has some, then Bushwolf, and Wrap Experts are the few I know of (we have bought all of them over the years). Plus a number of more generic non-photo style ones around online. No top notch ones are free though...