There is basically one good option for stock huge-motherfucker road bikes: http://www.khsbicycles.com/05_flite_747_11.htm
it's $1700 MSRP (can probably convince a shop to knock a couple hundred off) and that's a pretty damn good deal considering what you get.
The other possibility is to get a rigid 29er with a 72deg HTA in the biggest size (24") and put slicks + longer cranks on it. The Surly Ogre would be a pretty good choice there.