Hi Chris,
I tend to agree with Berkshire Boy - get used to rearing pigs for meat first before taking on breeding stock, otherwise it can be a huge leap into the unknown and unfair on both you and the pigs.
The added complication with the two free sows (which, I can completely understand, sound like a bargain to you) is their breeding history. Why has the one never farrowed and the other one only farrowed once? Did you ask the breeder? Did the one fail to get in pig, or wasn't she put to the boar? The big problem with sows/gilts is that if they're not bred from regularly, their fertility wanes, and you can have problems getting them into pig. With the one which has never farrowed (technically a gilt, not a sow, as she hasn't farrowed), I'd be very reluctant to take her on. With regard to the other, when was that litter - how long ago and why hasn't she been put to the boar since?
Obviously, I don't know the personal circumstances of the current owner, but I always feel it's a real shame when good, registered stock is not bred from. Such a waste, particularly when there are people out there breeding from real rubbish that shouldn't be put anywhere near a boar.
Good luck with OSBs - but get yourself some weaners and make life easy for yourself to start with. Great choice of pig for meat quality, litter size, and mothering ability (in my experience, that is - others may disagree!).