I.S.
Which ever milk type product you settle with I would suggest adding a multi-vitamin + mineral supplement specific for kids 6 mo to 2 yrs to his daily diet.
My daughter and grandson are doing well drinking Lactaid brand lactose free milk. Specialty milk products can be very costly. But if they drink too much it can cause them digestive distress. WIC in Oregon will provide Lactaid with a doctors note.
All things in moderation, it may be good for the family to experience the many varieties and different tastes available.