Chosen Solution

Is there an after-market set of hinges that would allow for the display to open 180º and lie flat? I have to replace the display assembly anyway and am wanting to use the display in portrait mode.

I dont think so as apple is apple and finding stuff like that with out heavy modding is near impossible. If you really need it in portrait mode for some reason get a nice older dell monitor that can rotate 90 degrees so its in portrait mode and just use that instead.