Well I definitely would get a 6 core minimum. Mainly I am just editing with fcpx and editing photos
I dunno if you need a 6 core for that... unless time is money for you and every second spent rendering is costing you money? I can edit 1080p just fine on my 3 year old quad core and my MP doesn't even break a sweat. Editing a large library of RAW photos is actually more taxing than 1080p video.