Separatory funnel - What size should one get?

[IMonIT2]

Hi, Swim is considering purchasing a sep funnel but doesn't know if a 2000ml is really necessary? Would a 500ml or 1000ml be just as good? Standard extractions performed would be approx. 1kg MHRB Note: Swim is also considering some Peruvian Torch extractions in the future.

 

[3six5]

my cat's 1000ml sep. handles 1gal jugs / half lb mimosa extractions fairly well. he says a 2000ml would be much better tho.