I have no idea if this applies to you or not, but I'll share an observation. Being a tall guy like yourself I notice that large bikes make it easy to have large saddle to handlebar drop. There must be something about designing a bike that you just can't get the head tube that high for bigger models (wheel size and fork size fixed? I don't know). So I would bet that with the largest model you'd be able to get a decent drop if you remove the non-essential spacers and flip the stem.