As I eat meat, ethically raised & slaughtered, whenever I have control, and try to avoid eating meat when there is any doubt, and am involved in raising cattle and sheep which also act as "grassland management agents", it's harder for me to argue against using pigs to produce organs, as they are used to produce meat.
However, I belive strongly that no-one should be forced to work with stem-cell-organ-pigs or implanting and no-one should be foreced to accept such an organ. However, healthcare workers often have to look after people in situations where they might not feel comfortable. Even the 1967 Abortion Act only gave healthcare workers the right to opt out of direct involvement in terminations of pregnancy, not in the care of a woman before or after.
Personally, I'm on the Organ Donor Register, as are all my immediate family and my partner, and my Mum, especially, is very insistent that she wants me to represent her views so as many of her organs as possible are used. A very good friend of mine developed chronic myeloid leukaemia at a very young age, and fortunately, an unrelated bone marrow donor was found, so she is completely free of the condition, and doesn't even need to take anti-rejection drugs - only happens with bone marrow transplants.