bluing is beautiful and has it's place on most all firearms. but PArking is about the best and easiest to perform. then if you want the ultimate in protection from weather and abuse Cerrokote over parkerizing. It's not going to be beautiful cobalt blue/black but i'll be damned if you can hurt it.
I have gone the Cerakote route. that finish is as tough as it gets. The rifle I took to Africa in Sept has a Cerakote finish and I was crawling on the ground with it in my hand and you could never tell it. I have 3 rifles finished in various colors of Cerakote and I absolutely love it. I bought my nephew a used Marlin 30-30 that I am refinishing the stock on and it is at the Cerakoters right now.
All Parkerizing does is hold oil, it offers no protection other than the oil that's in it. I've refinished piles of rusty parkerized rifles. Cerakote is super tough and flat, Duracoat is also plenty tough if done right but most colors aren't as flat, more of a satin.
Loc: Terre Haute, IN, USA
Just make sure you have someone competent apply your Cerekote. I took two guns to a well recomended applicator and the finish is coming off faster than the original blue. Not the fault of the finish, just the guy that put it on and me for taking it to him.