There is actually a custom ROM CM11 4.4.4 Kitkat for samsung mega 5.8
Link:
http://xdaforums.com/galaxy-mega/orig-development/rom-cyanogenmod-11-t2911381
I tried it and its working great and also u can apply themes!
Link:
http://xdaforums.com/galaxy-mega/orig-development/rom-cyanogenmod-11-t2911381
I tried it and its working great and also u can apply themes!