Pocketed coils are much more common because they’re easier to ship and they work on adjustable bases. I don’t know enough about springs to go over the differences between different companies and different coil options, sorry about that! Your choice for the comfort layer / pillow top, etc. is going to be a matter of your specific needs and preferences, and I don’t have any specific advice for you on that either.
I’d normally recommend 3" of soft Talalay over coils for her side and 3" of medium Talalay over coils for her side, and that’s for a few reasons. In short, Talalay is better at avoiding hip pain and shoulder pain and is better at filling in the gaps between your body and the mattress, which is called secondary back support and is important to avoiding back pain.