Can I replace one ford stereo for another ford stereo?

I have a 05 model fiesta fitted with a 4500 series stereo. As it is a double din model i am looking at putting in a 6000 series stereo from a 08 focus the bluetooth model, will I need any kind of electrical conversion kit or should the standard ford fittings surfice. I am aware that i will have to alter the facia and would appreciate if you could help me with that also, but not as important. with thanks, M Kirkby.