Hi there!
I'm afraid there is no JR-East/Central pass available.
Hmm - It's a bit tricky to decide what is the best pass for a 7 day trip. Here are your options:
The JR-East pass is only available in 5 or 10 day versions (¥20,000 and ¥32,000 respectively). In addition the JR-East pass will not cover you to Takayama, requiring the use of a transfer bus from Matsumoto for a further ¥2500 bringing the total for 5 days to ¥22,500.
In contrast, the nationwide JR Pass is available in a 7 day pass for ¥28,300 and would provide full cover.
Both tickets will require an additional ticket purchase from Otsuki to Kawaguchiko of ¥1100 each way on the non-JR Fujikyu line.
The return trip from Takayama/Matsumoto to Tokyo mentioned in (1) does pass by Otsuki/Kawaguchiko en route, and so in this respect will be the most convenient.
I think it really depend on how much travel you think you'll do on the remaining 2 days of your 5 day trip. If you arrive into and depart from Narita, then I think I recommend the 7 day JRpass as it can be used on the Narita Express (~¥6000) and still give you 2 days of flexible travel on JR lines around Tokyo. If, on the other hand, you arrive into Haneda, then I think the JR-East + bus trip from Matsumoto may be a better option.
Overall though, the prices between the two options is not that different so you should go with what you think will be the most convenient overall.
Hope this helps!