i used to get sterile urine specimin jars and freeze my EBM in them. They hold about 120mls. Otherwise i froze my milk in snaplock jars.
I used to express and when my twins were first born i was expressing heaps more than they needed. I ended up with a whole chest freezer ( you know one of those upright ones with the lid on the top) totally full. That is when the snaplock bags were better as they were more compact to store.
BTW EMB milk last longers in a chest freezer than a freezer that is attached to your fridge. (12 months in a deep freeze, 3 months in a fridge/freezer) so if you can store it in the deep freeze its better.
HTH
Odette