Color is more true in the 2nd photo.

US 6 for the basic stockinette gauge of 24 sts x 4 in

Mods:
--I slipped the first stitch of every row (knitwise on the knit row, purlwise on the purl row) which REALLY proved to be a good decision because when it came time to pick up the sleeve stitches for the sleeve cap section I just picked up every stitch that had been slipped and the numbers came out right).
--For the ribbed cuff I only did 30 repeats instead of 35.
--for the front buttonbands I still picked up 97 sts on each side even though I lengthened the body--somehow this worked out fine.
--for the neck, the only numbers that changed were to pick up 19 sts in between the front and back instead of 25 sts.