I appreciated reading your story as  my husband is almost in the exact same position except that he is older--64.  He was diagnosed with AA in November 99 and went through his first round of ATG--rabbit--because he was allergic to horse.  The first round was successful and his counts went up substantially and he was transfusion free for about a year.  

Then in March he was diagnosed with prostate cancer and under went radiation and seeds.  His counts had started to go down and he needed platelets for this procedure.  Finally, in May the doctors at Mt. Sinai repeated the ATG and cyclosporine.  He is basically on the same drugs that you are and his doctors are talking transplant but fortunately his sister is a match and it looks as if they are leaning toward this.  They are also considering a mini transplant.