Tamox or Arimidex???

Some background:  Had chemo x 5 mos.   Then I had bilat. mastectomy, axillary dissection and prophylactic oophorectomy.  Path showed 2 positive nodes (originally thought many, many positive nodes but never knew for sure since I had chemo first).   Onc originally recommended the oophorectomy because my tumor was ER+ and wanted to have me on Arimidex.  I'm 38.   So  I followed her advice and had the ovaries taken out.  Now she is saying that maybe I should be on Tamoxifen first because I'm younger and Arimidex can cause so much bone loss and I'd still have another 10-15 yrs of bone loss, although Zometa could be given.   I'm so confused and my anxiety level is out the roof.  Anyone have a situation like this and can share their experience?  My onc is asking me to make a decision between Arimidex and Tamoxifen.  She is worried that with so many nodes thought to be positive originally that I'm at a very high risk of recurrence.  Her thought was starting with Tamox and then after a year or two going to Arimidex.  But I worry about Tamox side effects....but Arimidex doesn't come without it's side effects either.  Her concern is that there just aren't enough studies out on surgically-induced menopause and the use of Arimidex.