In a 100 ltr tank the biggest batch you'll do is 60 - 70 ltrs. Think in terms of oil + expansion + methoxide + ullage space.
Experience shows you get far quicker complete processing if you use a large pump, say circa twice the oil volume/min.
Again from experience, the Leo pumps seem to be overrated, producing far less volume than stated.
Monos are no good as a processing pump. Way too low capacity and far too gentle with what it's pumping, but well worth having for moving stuff around if you can find a cheap one.