I read that NAN formula milk is the closest to breastmilk. However, there are a few types of NAN formula available, NAN Comfort 1/Pro 1 Gold/Optipro HA 1 Gold. Any advice on which I should get? Bb is 10wks old.

The main, most common one is NAN Optipro 1 - the others are basically just different mainly because of their manufacturing countries. HA formula are hypoallergenic ones specially formulated for children with cow's milk allergy - if your child does not have that, please do not use HA because it's bitter (not pleasant to taste) and might cause other issues.