How to navigate google search results in Safari 8 with keyboard?
Here's an extension that will let you do it in Google Chrome: https://github.com/nqzero/knogs

At the bottom of that page is a link to do the same thing in Safari (I can't link to it directly from here because I don't have the reputation for it).

I haven't tried either version though.

Personally, I use Mafuyu (http://wakabamac.blog95.fc2.com/blog-entry-1013.html). Instead of using J and K to navigate and return to open the result, you use 1-9 or 0 to open the result directly.