Man of Honour
This.If you are serious about this and will use them frequently go and get custom ear moulds with a level of attenuation you want. It wont cost you that much extra over constantly trying off the shelf products.
Most local audiologists should be able to sort this out for you.
My other half is a musician and found that the same filters are used in a lot of plugs for both motorsport and stage gigging - and the music oriented ones tend to be cheaper.