Just stumbled into the perfect sleeves for the NE-7, but I doubt I can get more. Succumbing to the frenzy over the SoundMagic PL30s, I bought a pair. I don't like them much (hey, they were $19 shipped), but in the package was a tiny pair of black foamies resembling the Shure olives, but smaller than the olive smalls and no sound tube in the middle, so they fit the NE-7 large sound tube. Rolled and inserted them, and wow, nice seal, didn't bloat the sound, etc. Unfortunately, they came from China, and doubtful they are for sale anywhere. But if anyone has both phones, give them a try. Assume they will work with the 8s too.
I was using the Comply T400s with the 7s, but they seemed too bulky, not good for long-term listening (though they sound good too). I can't use the OEM silicone sleeves, they just don't seal for me.