You can't predict meter failure in a D2H and both bodies are a gamble. But I'd get the one with the replaced meter -- 18K shots isn't a lot and the new meter just might have a lot of life in it.
The shutter is going to go 50 - 100K, I'd bet, or more... in the grand scheme of things, I dont think you are talking bout a big difference unless you shoot a whole lot.
Okay, now that Nikon confirmed this policy in the last 24 hours (no guarantee before today that Nikon would do this post-warranty), then the choice was easy.
actuations on the nikons honestly are pretty trivial. I know some sports photographers who shoot with nikon and get half a million shots a year on a body with no mechanical failures. D2H is a pro camera with top quality construction. I easily put 5-6k shots in a single day of shooting on my D2H, and don't feel like I have anything to worry about honestly. Sorry to hear about the wrong actuation count, but like i said I wouldn't really be too concerned.