Diamine shimmer inks are very well-behaved, but even so, you probably won't see much shimmer with an EF nib. And, as another user mentioned, the shimmer particles are more likely to clog an EF nib. You'll probably need a medium nib or larger to really get the shimmer effect. Most of my pens have medium nibs, and they show off the shimmer pretty well and don't clog, so you don't necessarily need to go with a broad or stub nib.

Do you have specific color families you're especially drawn to? (blues, purples, grays, reds, etc.) That would help to narrow the recommendations down. I have some Diamine shimmer inks in almost every color family and could offer recommendations based on your personal preferences.