How big were they?
What was the kill out weight at the abbatoir?
How will the meat be packed - vaccum sealed?
What weight / girth were the pigs when slaughtered?
How long is a piece of string

- It seems that you killed them too young to me, but maybe they have
got fat quick from the feed you gave them. Did you not get any information from the person who sold you
the weaners - advice etc.?
Unless you can answer some of the above questions no-one can tell you what storage you need. As they were only with you for three months, they might both fit in one chest freezer, as I doubt they would have
been anything near the weight to slaughter.