I agree with what a couple of others have said here already; the largest I'd personally go is probably 17", but I just went through the decision process and my choice was exactly your before picture! But also like some others have said, big wheel & tires look wicked cool when the car is sitting down on top of them with the tops well inside the wheel wells. I'm not sure what you'd have to do clearance-wise to swallow those tires, but if that's a possibility I'd love to see it when you're done.
Later, Jim