I also tried this watch on to get an idea of what it's like to wear an insanely oversized smart watch.
I am someone who generally prefers very slim, sleek watches with a classical size ratio, so as a comparison, here's me in my daily wear watch (Citizen Stiletto) which is 36mm across the face:
Stark difference. I'm still on the fence about 42 vs. 38, but, I'm sure the 42 would be passable, if maybe a little big still. I would just go 38 but the notion of even just a little more battery life in the 42 forces me to consider it.
BTW, I keep seeing people say they printed the apple watch size demo thing and it was the same size as their pebble... no it isn't. The smallest shipping pebble, the steel, is still 4mm taller than the apple watch and the hideous original model is significantly bigger than that. You probably printed things wrong.
However, that said, the pebble steel is probably the closest sizing analog you can find right now. It's only 4mm taller and slightly narrower. If that looks/feels good then the 42mm Apple watch will be fine. If it seems a little big, go with the 38. The Moto 360, however, isn't a very good analog because it's round and round watches look smaller than rectangular ones when they share the same size across the wrist, due to the corners of the rectangle.
My wrist is 167mm where I wear my watch, for comparing with OP.