bundle of joy -
Yes you could. Obviously breast milk is better. After all the recent hype I am a bit more concerned about formula so if you can get hold of goats milk then maybe to that.
I must add that Dylan thrived on breast milk but didn't on formula at all. His chart took a nose dive. We don't know why, but just our experience on the matter. Dylan's paed was also very clear about the benefits of breastfeeding and when Dylan got the RS Virus he pointed out that it was only due to breastfeeding that Dylan didn't land up in hospital so if you can express and freeze then that is wonderful.
It is tough having a life and breastfeeding and you are on leave for 6 months which is a long time so I really do understand a mom wanting an alternative plan.
I honestly must say that formula was a blessing (he slept better) but along with it came problems like constipation and vomiting and all so it wasn't great for us.
Luke seems to be in a league all of his own so I am sure he will be fine on both. Try to exclusively bf for as long as possible. Ideally they say 4 months.