buy the screen that masso912 specified, the 1920x1080 screen.
after you install it, (remember to install the patched dsdt before you shut the machine down the last time with the old screen) upon reboot it will display whatever resolution you had the old screen set to.
then go to system preferences-->displays and choose 1600X900. it will work fine.
that's what i have my screen set for right now.
i decided that even tho the text is much crisper and sharper at 1920X1080, and more content fits on the screen, i would need reading glasses, so i shifted to the lower resolution.
i haven't played a movie on it yet, but i would imagine i might set it for the highest resolution for watching the movie, then set it back to 1600x900.
it's still FAR better than the crappy oem screen and the 1344Xwhatever resolution the old screen delivered.