I prefer to use this handy [url="http://www.kellymom.com/bf/pumping/milkcalc.html"]calculator[/url] to determine how much milk they might need as it gives a range not a set amount; click on the purple text to open the link. DS2 never had a 120ml bottle of ebm, let alone at 8 weeks.
This [url="http://www.kellymom.com/bf/pumping/index.html"]link[/url] has heaps of info on pumping and storing ebm.