Get a couple of weaners. Raise them for meat the first couple of times and then breed.
If you are going to breed, suss out your market. It may be easier to find a market if you go down the rare breed route and finish them yourselves. There are butchers who specialise in rare breed pork. Pubs and restaurants too, are increasingly looking at ways of marketing their food. If they can say "Our pork comes from a farm just down the road and is a breed that you can't get anywhere else", that's great for them and you. They will need a steady supply, though. Cultivate relationships and create your market. That's what we've done and it is working well, so far.