Any of the rare breeds will be great for your woodland, they'll be hardly and happy there.
I'd suggest you start by having a few "weaners" - typically 8 week old pigs, and grow them up for meat.
Whilst some might disagree, I would suggest you start with a lop-eared breed, they tend to be more docile, so saddleback, Gloucester Old Spot, OSB, Large Black amongst others will be fine. Tamworths are a prick eared breed, and more feisty - maybe have them as your second lot once you've got used to some lop-eareds.
Once you done that, you can start to think about moving onto the breeding stage, and two girls and a boy will work quite well, as if you alternate the boy can have female company all the time.
Farrowing outside is perfectly fine, but you will get a higher rate of piglet mortality, and sows can be harder to handle in farrowing arks than in buildings, but many do, and don't let me put you off.
[advert on] Sounds like a good book on pig keeping is what you need, or even a course - we do both
www.oaklandspigs.co.uk - other books and pig courses are available [advert off!]
Whatever you do, you starting right by asking questions and doing your research !