LMC sells some
trim but it's not quite the factory stuff. Lesser quality, and not quite the same design IIRC. The OEM stuff is (like many things) discontinued or unavailable last I heard.
I think you would probably be okay to pull the old stuff off and run without it. You run the risk that there may be some fading that will show up a little if you pull the moldings, but you could always pull one of the small ones and see how it looks, then reattach it if the paint is faded badly enough that you can tell. They actually look pretty good without it, in my opinion.
Here's NMB2's truck (2wd and crew cab) it's a similar color though so you can get an idea what it looks like.