Hey,
I'm 6'-9" with a 38" inseam, and run about 235 lb. Can I ever relate to your friend's problem getting fitted properly! It can be done, however. Keep in mind, however, that durability is very important (especially at his weight, so things don't break under load and stress due to clydesdale-ness).
I started about six years ago with an off-the-shelf Giant Rincon hardtail MTB in the XXL frame size (25.5 in. or 65 cm). It's got the stock seatpost, and I've alternated between a riser 45 degree, or a 90 degree stem, with 130/140 mm extension (depending on what I'm doing). Fits great. Had to get a wheelset built with RhynoLite XL 36-spoke due to the my clydesdale-style of riding. I use this bike on and off the road, and it's held up well (albeit after about three component upgrades).
I then discovered eBay, and started searching under "Complete Road Bikes" with the keyword "tall". I found an old-school Takara steel-frame touring bike with a 27 in. (69 cm) frame. The frame was good, the rest was junk. I added my own components, and came up with a real nice flat-bar road bike. I have a 350 mm mountain seatpost and a mountain 130 mm riser quill stem to stretch it out some, and it fits great. I ride that bike around town quite a lot. It's got an inexpensive Nashbar Velocity 27 in. 36-spoke wheelset, which seems to be holding up well (my LBS retensioned/trued the wheels for my weight).
I finally found my best bike on eBay a while back. Again, the frame was excellent but most of the parts weren't (the owner apparently parted out the good stuff and replaced them with not-so-good). It was a 29 in. (74 cm!!) sport/touring frame custom made in 1980 by Mike Appel, who was one of the first Trek Bicycle frame builders. Columbus tubes, hand-cut custom lugs, etc. The stand-over is 38 in. (my inseam!), and I have a righteous "fist-full of seatpost" showing, but no more. The frame is just the right size. It's stiff, but has a good ride quality. I have a 130 mm Nitto Technomic stem, Nitto 48 in. "Noodlebar" drop bars, and 175 mm cranks. My LBS built a clydesdale-proof Mavic CXP-33 36-spoke/14 ga./105 hub wheelset to round out the package. I did my first century on it about a month ago, and having that bike made all the difference. I've had people say I should look at 180 mm cranks, but honestly the 175's are the best fit for me.
I still check eBay for tall bikes, and there seems to be several listed in the 67 cm size at any given time. 69 cm would be better (your friend could probably ride any one of my bikes, with the addition of a longer crankset, say at least 180 cm). I wouldn't go any smaller frame than that for a road bike, however, and I would recommend looking for touring or sport-touring geometry (longer chain stays and top tubes). Granted, these are for the most part old-school steel frames, but given the size and weight factor involved, it might be better anyway.
He might get lucky if he keeps checking. I saw a custom 75 cm bike last year.
Your friend could always go custom, for beaucoup bucks. If I ever was to do so, however, I would have the Appel frame replicated to the exact same dimensions. It fits me that well.
Hope this helps...
