Curious wrote:

Which commercial super-tweeter should I consider for maximum treble
with maximum SPL?

If you by "super-tweeter" mean drivers that extend beyond 20 kHz, there
are very few to choose among. How about the SA 8535, also known as the
Ribbon Compact Driver ?
Data sheet:
http://www.wbvbeheer.nl/wbvportal/st...pdf.php?id=135

Stig Erik Tangen