What's wrong with what is there already (apart from its falling apart after 16 years)?Yuk!
Seriously, id say strip all that off and replace with a foam setup. Try Classic Acoustics in Telford.
I used a sandwich. two layers of 15mm acoustic foam with a polymer lead sheet between, then shiny aluminium foil bonded to one face and self adhesive to the other.
Really reduces the noise but has 2 other benefits...
1. you can wipe it clean rather than absorbing oil etc
2. big benefit is that the ally reflects light into the engine bay making it easier to work down there.
seal the edges with aluminium tape