Given the price bracket, I'd lean you more towards the RE-ZERO instead of the RE0. Personal opinion, but I feel the RE-ZERO is a rather significant improvement over the RE0 in many ways and worth the price step. The dynamic range is significantly improved, the sound stage is significantly improved, and you don't need a powerful amp to drive them.
Versus the RE0, I can see how the HJE900 wouldn't decimate them. I haven't yet used the HJE900 personally though, so I can only relate to reviews/user comments on the earphone.
I will also point you to Klipsch's Custom 3 as another option. While the RE-ZERO is lean and clean, the Custom 3 is a little more hearty and energetic and offers a better sound stage to boot. Both are great products at the $100 price point, and both are very likable. What about the HJE900? I don't know. I just haven't used a pair yet to comment on how they relate. From readings, they certainly are sitting at the same level though. I also know the oem version of the Radius DDM earphones are around the same price point of the HJE900 too and yet another great sounding earphone.
Just keep reading reviews and user comments and get a feel for how each may fit relative to your tastes. From a raw SQ standpoint, you probably can't go wrong with any of them. It's simply a matter of which one best fitting your personal preferences.