CEPs
Looking at the website I can't see what it would offer over and above CEPs?
I use CEPs the whole time in a very noisy aircraft and now won't fly without them. I even spent the extra money on having custom earpieces made as I thought it would be easier and more comfortable than fiddling about with the standard foam ear plugs - only to find that the custom ear plugs are less comfortable and don't block out as much noise!
If it was my money I would fit CEPs - you can always buy custom earpieces for them later if you really want.
Have also had nothing but outstanding customer service from the guys at CEP.