If you want to fix your Google search to a specific Google location, or a specific search engine, I recommend that you download and install the free plug-in Glims:
which not only does that but much more equally useful stuff! Such as enabling Safari to run full-screen, and more.)
(It adds items to Safari Preferences).
Not only does it already list a number of search engines and regions, but you can also add any other search engine not already listed in Glims by using the method described here:
Just enter the name you give the search engine in the name field, and the URL for it in the Query URL field.
Now why would Apple make it impossible to change your default search engine?
Because they are in bed with google.
What happened to giving us a choice?
This kind of thing makes me mad.. but not surprising because google are crooks.
I bought a mac 9 months ago and have found so many things I dislike about it.. and here is yet another example..
It was a big mistake and I will never buy anything apple again.