Might be tough to find. Not understanding why you want a new one though? Wouldn't you have just as much a chance of scratching that one? Can you not buff or paint the bumper you have? What will you do with the original bumper?
I'm pretty sure we're just exiting the tail end of the 'too early' stage as far as aftermarket parts go. I haven't gotten any confirmation on my hypothesis, but I imagine that the market for parts is going to increase if Toyota takes the iA under its production wing. Being so, I think there'd be a harder push from TRD to start making parts, and competition would soon follow.
Speaking of parts, whatever happened to the RS*R springs / coils? Did they just drop the ball?
I'd be surprised if TRD bothers to do any parts for this car. With so much existing aftermarket support for Mazdas already, my guess is they'll let those folks take the business rather than invest R&D in a non Toyota platform.