Congratulations on the pregnancy and the twins.
The smart money says you will definitely have a C-section under the circumstances. Breech is always tricky, because the head does not have time to mould in the pelvic canal. If you deliver the baby up to the shoulders and then cannot deliver the head, it is difficult to then pull the baby up again from a C section and would be the worst of all worlds. In the meantime, baby 2 is waiting, inside a contracting womb, under some stress.
Your BP/ pre-eclampsia is probably more of an issue than the low iron, although post-partum bleeding is more of a problem with twins, because it takes longer for the uterus to contract down as it is so big.
If you are big, then there is also a chance that your babies are big for dates (esp if you have pregnancy related diabetes.
Talk to your obstetrician, but be realistic. When you are pregnant it is difficult to imagine being a mother; the birth is the focus of all your attention. Actually, it is just one moment in your life with your children.
Finally, I had twins, both head down, and delivered vaginally, despite not feeling strongly about it. It was not magical or wonderful, it was frightening for me and XP. My kids, who are fine, are not in the least bit interested in how I delivered. I had high forceps for both (so 4 lots of forceps) which caused bruising to the boys and more serious damage to me, leaving me with double incontinence problems. Considering colostomy or other surgery now, because it is hard to work.
I would advise you to adjust to the idea of a C section. It can still be lovely, and the important thing is that you are and your babies are OK.