HI guys, i am currently using a sony A7ii with a 28mm lens, thinking to get into mostly portrait and events kind of shoot. I am not too sure if i should get a 55mm f1.8 or the up coming 24-105 f4 lens or save up to get the 24-70GM lens(in which i will need to save up damn long), i have heard very nice reviews on the 55mm thus i am having my dilemma.