The question is: Are earplugs really needed when replacing the pipes with say, Sil High mounts 105dB. I would eventually like to get high mounts, but don't really want to have to wear earplugs just to ride around.
There are LOTS of different kinds of plugs and, except for the custom ones, they're all cheap. So keep trying different kinds until you find one that works for you. It's a very personal thing as ear canals are all different sizes and shapes.
It's worth investing the effort to find a brand/model that is comfortable and provides the kind of attenuation you want. I can't remember the brand of the ones I'm now using so I can't give you specifics (and they may not work for you anyway).
I Googled "ear plugs" and "motorcycles" and found a lot of choices.