Do your research on the doctors and facilities. However, after you choose which one is best for you and that your insurance is accepted at (with no issues of renegotiations that might affect you), there is a battery of tests that you need to go through to see if you are a good candidate. This is so that you have the best outcome. The tests can take some time to do or if you are in bad shape by the time you get an appointment (like I was) they may rush the timing of all of the tests. I had 4 days of tests that I just pretty much spent the whole day at the hospital for tests. After all of the tests are done they evaluate your condition and may or may not put you on the wait list. Based on your condition is the number that you are given from 1 (perfect lungs) to 100 (pretty much its over). Most people receive a transplant from 35-50. I had a rank of 75. I had my double lung transplant and am able to do so many things I wasn't able to prior to the surgery.
Right now you might be contemplating, but you might get extremely worse quickly and not really have the time to consider where to go. So I would advise that you do the "leg work" now and then if you decide to withdraw later you have the option.