Obviously, I only know what's been written, but I'm a little concerned that your brother feels he's being pushed into the transplant before he's ready. Maybe it's simply nerves and a normal fear of the unknown, but I think it's important that his thoughts be heard. Transplant surgeons are quite prone to the "More Transplants Quickly Better" mentality, and everyone wants your brother to be healthy again, so is it possible they (and perhaps you too) are dismissing your brother's concerns?
So much attention is paid to the prospective living donor's autonomy or willingness in making the decision to donate, but very little is given to the recipient. That a recipient wants a transplant, and will put their loved one at risk to have one, is just assumed. And it shouldn't be. The recipient deserves to make the decision s/he thinks is best for her/his care.
Of course, I may be reading more into this than necessary, but it's something to think about.