I would say Macy's, Lord & Taylor, and Penney's sometimes. That's where this gal shops and I have no problem finding clothes in styles that are nice, feminine and not "too young" for me. As for a wig, just go to a wig salon. I did that a few years ago and was so surprised at how welcoming they were. They are able to suggest styles that will go with your facial structure and skin tone as well as age.
For shoes I love Clarks. They are stylish and very comfortable. No 5" heels, but as you said, we tall girls don't really need heels like that.

If you know your sizes then just go to the mall and have fun.