Edit 4K video...MBP or iMac?

i got a new camera and want to start making some videos for fun in 4K. My 2011 MBP just won't do it.

Which MBP is good for 4K editing? Secondly, is the iMac a better value? Editing video and watching 4K content is the only reason I am looking to buy a new laptop. I usually use my iPad Pro or work laptop at home