I 6'4" and know the tall situation all too well. I went with an older bike, partly because new bike sizes are limited, but truthfully because money is more limited. It's a longer, more difficult road to dink around fixing up a bike, but it can also be rewarding. Currently I'm fixing up an old 80's Fuji that has a 27" frame (68cm) posted over in the C&V section here:
http://www.bikeforums.net/showthread...ate?highlight=

When I'm done with it I suspect to be every bit as good for me as if I were going out to buy a new LHT at less than 1/2 the price. The biggest cost will be the custom wheels I eventually buy for it, but then I'd have to build special wheels even if the bike was new. Big old frames are out there, and they tend to sell for a little bit less because there's a smaller market for them. I don't race, so older equipment is fine with me, if I did race I suppose I'd have to invest in a custom build. Interestingly the fuji is actually a little too big for me because I'm more lanky than legs, but it was cheap. I paid less than $100 for it in decent condition the winter before last and rode it all last summer for club rides until I trashed out the old steel wheelset.

If you go the old route, there's a lot of resources online to help. I can give you links if you want.

Good luck,

Jim