Thanks for the input.

The 40mm of spacers is really 25mm of spacers plus the headset top cap which is 15mm. My initial thought was to go for the XL since since 40mm is spacers sounded like a lot, but when I went into the shop they had a large built up with 40mm and an upturned stem and it didn't look bad.

When the fitter was adjusting the height of the front end I really couldn't tell much of a difference, so I think I have some flexibility there, but changes in reach were much more noticeable. The difference in reach between the 2 frames is 19mm. Getting the XL doesn't leave me much room to play with if I want to decrease the reach in the future, especially since I would have already shortened the stem down to 100mm.