The most important measurement for me has become stack height. 400mm seatposts can provide adequate seat height on a large range of frames. Aheadset stems available in everything from 60-140mm open up top tube limitations. However, at the expense of effecting handling via weight distribution. But, it's stack height that seems to be the limiting factor for me. I need the bars high enough and far enough away that I don't bang my knees into my elbows. I've had a couple of lbs saleskids try to convince me that they can fit me on a 58. They only way I can accommodate the increased drop to the bars, is by moving them closer (less reach). Which results in the dreaded knee/elbow interference. I can understand the OP's thoughts that he needs a reasonably large frame. At 6'5" and a 955mm cycling inseam I can't consider anything less than about 63cm with a 60cm TT. Anything less doesn't seem to support the 64cm of stack height that I need.