Lisa,
Just saw your thread. I know you're probably at the Doctor as I write this, so best wishes and prayers for you. I hope you ask your Doctor all of these questions - the doctors are the ones we have to put our trust in.
If they're telling you they can do the heart surgery now and that will keep you *alive* and eligible for the lung transplant, what other choice do you have? There are many people on this board who have had more than one major surgery - none of them by choice.
Also, I wanted to share with you that I have an acquaintance who had cystic fibrosis and had a double lung transplant at age 22 - she has fully recovered and is doing fine now, two years post-op. If you're not ready for the lung transplant yet, do whatever they're telling you it will take to get ready and stay eligible.
That's what I'd do. Be sure to post when you get back from your consultation today and keep us all up to date on your situation.