i3 ears are EASY to mod. There's even a template online showing where to cut. I got it saved if you need it. But good luck getting dye i3 ears. I picked up a pair of blue ones for one of my flex's, but wasn't my first choice. At least it went well with that color scheme.
A couple places make custom i3 ears, it'll just cost a little more, which is kinda doodoo since you'll still need to cut em to fit. Gangster PB makes some, and probably Stingers. Won't be the same material, though.
The standard e-vent ears are easy to mod, almost identical to jt soft ears except for the shape. The nicer e-vent ears are more like the i3 ears in terms of materials, but have a rubber inlay with metal mesh that extends most of the bottom half of the ears. I don't think you would need to trim that part, but you would be cutting it close... haha! "cutting it close!" *badum tsh*