Good advice, all. There are two other points:
First, Estradiol can be taken sublingually (dissolved under the tongue), avoiding the digestive tract and reducing the stress on the liver. It also gets much more of the medication into your bloodsteam than swallowing it would.
The only disadvantage to the patch (other than cost), is that if you are concerned with possible side effects, there will be a time delay between removing the patch and the concentration of estrogen in your body dropping off. This is true with pills as well, but the delay is supposedly geater with the patch.
Pills have the advantage that dosage can be easily adjusted, ramped up or down. You simply go from 1 a day to 2 a day or 3 a day. Once you've bought a supply of patches, that's it (although you could use multiple patches, I suppose).
The best bet might be to start with low dose pills, adjust dosage as needed, then switch to the patch once base levels are determined. Remember, all this should only be done under a doctor's supervision & frequent monitoring, as everyone reacts differently and an approach that works well for one person may be extremely dangerous to another.