supplemental milk for a breastfed 11mo

[Hamandcheese]

My 11 month baby is still breastfed plus extensive but a bit haphazard solid meals. when I return to work, he'll need 7 milk feeds a week when he is with his carer - I'll have some EBM but not enough.
What is BEST for him for those few weeks before he's one: formula / 'follow-on' / straight to cows milk cos it is really a bit moot at this age (he'll still have at least two breast feeds a day).
I intend to quit breastfeeding at 1 year old.

I would like to know this too as DS will be in nursery at 11 months, hoping to still bf twice a day, will express as much as I can but not stress over it

If he had formula would he still need the multivitamin?

I would offer cows milk, he probably won't take it to begin with but if he is having at least 2 BFs a day anyway and some food he will be fine.

why the multivits? never used these with the older children: do they simply come in a baby-type packaging with a dropper?
what about all those yummy omegas that I've been beleiving are in BM?

cows milk would be SO MUCH EASIER.