Supplement with formula or cow's milk?

Useonfire

I have been EBFing (except for recent addition of solids) since DD was born. We are currently on a major nursing strike (I really think due to extreme teething) and I'm worried we won't recover.  She's 8.5 months and I'm hoping I can get her through until 10 months on BM.  After that, should I supplement (one bottle a day) with formula or cow's milk? I literally can't imagine her willingly taking formula since BM is so much sweeter. I can't honestly imagine her taking WCM either, based on the fact that she much prefers solids at this point to either nursing or taking a bottle of BM... 

At this rate, assuming nothing else changes in my supply, I can easily produce at least 20-25oz a day with 3 pumps. How much milk does a 9-12 month old baby drink? I have no idea because I've never pumped other than 1x/day (before bed) her entire life and she was just nursing so I'm clueless as to her intake in a day.