Mine were also LB x GOS, they were all around 85Kg live weight. Killed out at around 50Kg and we got around 35-40Kg of useable meat from each of them. So you're probably looking at 100Kg in total. I would say you'll need a big chest freezer to fit them in (unless you're doing lots of curing)
I've got to say too, that this is some of the nicest pork I've had. Much sweeter than any of the other crosses I've had and without doubt the best bacon ever ! but I've not taken any tamworth crosses for bacon - that's next
(and although they were quite small in baconer terms, the eye of the bacon is still a good size)
HTH
Karen x