This seems like a great idea. Unfortunately most of the recommendations seem to not be supported on my MacOS machine. Also, when I paired it down to the ones that are supported I wasn't able to connect to github. :( Very annoying.
Use Homebrew [1] to install 6.6p1 with its bug fixes and enhancements:
brew install openssh --with-brewed-openssl --with-keychain-support
Reference: How to Update OpenSSH on Mac OS X at http://www.dctrwatson.com/2013/07/how-to-update-openssh-on-m...
FWIW, this is what I have in my config file on Mac.
Ciphers aes256-ctr,aes128-ctr
MACs hmac-sha2-512,hmac-sha2-256,hmac-sha1