If I am buying this many I want some sort of a discount obviously.
I usually buy bulk stuff from usplastics.
Their price break for 6-7 gallon buckets is 16
they are probably still the best.
for 10 fermentors, buy a pack of grommets and drill your lids.
Here is the link for 6 and 7 gallon buckets from usplastics. Note that the lids are sold separately. http://www.usplastic.com/catalog/item.aspx?itemid=23470&catid=752