Lovely cities, but beware of the summers. Summer is a bit tooo much hot there, and temperature may even cross 50⁰ C over there. So plan in autumn or spring.
Btw, you should also consider Kurukshetra as an option, if you want to see something more "religious".
And there are a lot of hill stations in Himachal Pradesh / Uttarakhand.
It is all about taste. And India have places for all the tastes. Like if you like more wildlife, tigers, Bandhavgarh National Park or Jim Corbett national park is a nice idea.
Also, don't forget Taj Mahal, which is one of the most beautiful monuments in India.