I'm not sure if the R-50 will have enough bass for the OP's music? But I might be wrong, I haven't listened to them myself, have only had the dba02.
EPH-100 is nice, but its deep insertion put the driver so close to your ears, it seems that durability can be a concern due to moisture build up during workout.
I think the GR07 is a better IEM for running, and sound nicer to my ears than the EPH.
As for the se215, the cable of the clear colored one turns green easily especially if you take them out often. The black ones don't have this problem. Other than the color, I think they are the same.