If budget is an issue Bikes direct has a few models that come in a 64cm frame.
If used is an option, ebay is a good bet. In the 70's and early 80's you could get 27" frames (~67-68cm). I think the trend toward double butted tube sets put an end to this: All the 27" frames I have seen used straight gauge tubing, mostly ChroMo, as usually only the higher end models had the option for the really big frames. I've seen several such bikes recently sold on ebay for $100-$150 range.
example 1
example 2
If you use the options on the left side of the ebay search, you can check boxes for frame size. Be sure to check the "unspecified" box as well as the two largest options....as many listings don't give the frame size in the data section. It is pretty easy to spot a tall frame in the photos, even thumbnails...focus on the headtube.
The good news is that many tall bike frames tend to have a too short top tube for folks with "normal" proportions. Us folks with long limbs and shorter torsos actually fit pretty well on them though.
PS: Don't have your friend PM me, cuz I don't like tall girls....Nope, not at all. Especially not red heads, or blondes, or brunettes. I like short ugly ones, preferably bald.