My ring isn't as unique a shape as you (or Rachel's), but my wedding bands don't fit around it either. I actually prefer that look and don't like when the wedding bands are shaped around the e-ring. Now, that's just my personal opinion, so take it with a grain of salt. I bought a wedding band for both sides of my e-ring and I like the versatility it gives me. Sometimes I wear all 3, sometimes I wear my e-ring with just one band, sometimes I just wear my band(s), sometimes I wear my e-ring with one band and the other band on my right hand, sometimes I wear my e-ring with my grandmothers plain gold band. See what I mean about versatile?
I woudl def talk to a jeweler and see what they suggest. I am not sure that you could wear a band that doesn't fit against it, since your's is def a more unique shape then mine, but check it out anyway, just to be sure.
Good luck!