I wouldn't recommend the EPH-100 or any other IEM with a nozzle-mounted microdriver if you have narrow ear canals. The X10 fits your requirements pretty well but it's not very durable in my experience. The GR07 has good but not great isolation. Out of those four it seems like the W3 would be your best bet.
I also think the RHA MA750 might work well for you. It's not very light but the weight is offset but the molded ear hook bits. Isolation is surprisingly good - better than with the GR07 IMO. Build quality is outstanding. Sound is very competent, at least on-par with the EPH-100.
Sounds like a lot of others are recommending the W3, but you only graded its isolation and comfort both as a 3.5/5. Will it fit well with my narrow ear canals?
I'm also interested in the MA750, it's only $130 at amazon even with the remote and mic, which are a huge plus for me. How do they compare to the W3 if I only care about comfort and isolation? The stainless steel construction sounds pretty durable, but heavy. At this point, as long as the sound quality is similar I don't mind subtle differences.