500d

hello I currently owned a 700d,500d, and eos m3. but I am using that for 1 set of event. this year I am planning to get a 5d mkIII is it better to buy 3 eos m with Magic lantern together with 5d or it better to buy a 1 gh4 or other cheaper 4k camera together with 5d? I am not shooting with...