Question for new NEX-7 owners (legacy M lenses)

I have three old leica R lenses and I recently inherited a series of old M-lenses. Because I no longer shoot film, I plan to pick up a NEX-7.

In doing my research it seems that there are a broad range of adapters to choose from. Some are > $100, some are

Which adapter(s) would you recommend for leica (M) / leica (R) lenses?

Thanks!
Ram