I don't really think rep ranges will make a huge difference between the two. Diet will make a big difference and genetics will be a big determining factor. Some people look like athletes and just plain won't build big round muscle bellies so they are more suited towards physique.
The nice thing is of you want to stay at a certain weight and notice you are growing a little more then you should you could back of the volume/intensity and or cut calories a little bit. Or you could always keep building and cross over into bodybuilding.
Just my opinion.