Best JRPass Option

It will be our first time in Japan in January/26.
We are planning to stay in Tokyo and visit Kyoto and Osaka with also a one day trip to Nara (from Kyoto or from Osaka) and one day trip also to Yokohama (from Tokyo).
Our plan is:
01/10 - 01/13 Tokyo
01/13 - 01/16 Kyoto
01/16 - 01/20 Osaka
01/20 - 01/27 Tokyo
I am on doubt if I buy 7 day, 14 day or if it is better other alternative for transportation between cities and also the one day trips to Nara and Yokohama.
We will be in 3 persons at the total.
Thanks for the help.