Hello
I can't help with the pigs, but I just wanted to say, go and speak to your local animal health department first as well. I have sent goats to both Northern and Southern Ireland, and despite the fact that Northern Ireland is a part of the UK, there can be issues with getting animals over. This is mostly down to the fact, that if we have a disease here that is not in Ireland, then obviously they do not want it introduced. All exports to Ireland were stopped during the Blue Tongue panic, and obviously during the FMD times as well. I had 2 goats living in my garage in isolation for 6 months once as they were due to go to Ireland, but FMD broke out, and all exports were banned. They were supposed to be in isolation for 30 days, and it ended up being 6 months. Fortunately they were kids and were just young. Also fortunately, our buyer was happy to pay for additional bills from our vet, as blood samples had to be taken extra times because of the delay.
I am not trying to put you off, just stating it might be more complex than you first thought.
My first ports of call would be the local animal health dept, and then the OSB society like Mandy says.
Good luck!
Beth