You need at least a 63-64. I'm only 6'4", and need a 61cm. Forget Giants XL, they are still too small and most carbon frames are not properly scaled for taller riders.
I would look to steel frames or CD ally frames, avoid CF seatposts, pedals, avoid Ti pedals (unless you are somehow less than 180lbs). You want to avoid having to use long seatposts.
Try used, hard to find, but also take longer to sell.
(that Trek 2100 is sweet)