I've always wanted a longer History record in Safari, and since last November I've had it. If you go into the Safari prefs file and change the following lines, I think you'll get a full year of History recording:
Quit Safari, then open com.apple.Safari.plist, located in your user's Library/Preferences folder, using your favorite text editor. Search for
WebKitHistoryAgeInDaysLimit, and change that section to look like this:
<key>WebKitHistoryAgeInDaysLimit</key>
<string>365</string>
<key>WebKitHistoryItemLimit</key>
<string>9999</string>
I don't know whether there is any negative effect to changing these parameters, but so far, my History appears to work correctly and Safari seems stable. Feedback or comments appreciated.