Which dslr 25fps loads easily to iMovie without converter? One around £500 or less please?

The apple list is very long with all sorts of extra info and I feel baffled - one or two best buys to use with imovie would help me. Or do I need to get

final cut pro x ? but gather that is not straight forward without converters either.

Does the conversion of files alter the quality of the video?

I want to just put the card in and it go!