If it was unflared, a 14"/15" staggered combo would make more sense.
It isn't common, but just because it isn't common doesn't mean you should do it. I'm putting staggered diameters on my hatch (not 14"/15")
Brett's car obviously looks cool as hell, but not better than if it had 15"s on the front IMO. The wheel arch on the flares is (or at least LOOKS) like a bigger shape and visually dwarfs smaller wheels.
Toranas with 13"s for example look cool if low, but flared they look like a joke (even if the wheels are wide as hell).
15"s all around is certainly a safe look.
If the car is low and the wheels have nice aggressive offsets, it'll look better than most Toranas because that's what people get wrong.