Hi it depends on hoe many days of trip you are planning.
the destination you have mentioned are on different direction and may consume almost a full day to travel from one place to another . Like Shimla to manali is totally hilly terrain and it might take 7 hrs . You can club McLeod ganj , dharamshala , Dalhousie as they all are nearby and cover most of the places . similarly if you are planning for Shimla region than can cover kufri , narkanda , theog ,chail etc . for Manali you can cover Kasol , Parvati valley , kullu , Manali , rohtang pass . further you have to analyze and plan out . hope this would help !