I'd say JC Penney would be a definite no, but Macy's or Lord & Taylor could work and have a lot of variety.
I think it's an absolutely fantastic idea -- definitely one I would have been thrilled to get. (I got a variation for my college graduation present -- a sewing machine, so I could make my own clothes!

)
I just looked at the websites of all three stores (Banana Republic, Gap, Old Navy) to be sure my now-5-years-out-of-date recollections re: business clothes are accurate. They seem to be. Banana Republic has a lot of great business wardrobe staples, the kind of thing you can get and then wear various ways/ add various accessories, like:
Then add a skirt, too:
I had that basic idea in dark chocolate brown lightweight wool, wore the heck out of it, together and mixed with other pieces.
Anyway, I think it was really smart of you to figure out this gift, I can't think of anything better.