I think you're proposing nearly the same setup as I now have, the 12k lb hi-perf draw bar, but I have 1000lb bars. You'll need the 1200 pounders with the slide-out I'd expect...
Just make sure that the top of your hitch ball will fall into the 19" range when mounted, as I doubt you'll experience too much rear-end 'squat' when you put the tongue on it.
Other than that, I'd think you'd be right in the ballpark, and you've certainly got a heavy enough truck. No such thing as overkill IMHO.
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"