You can replace the wipe as long as you destroy the old one first. You cant store spares.
The griffin rev 9 in k config is right at the sweet spot for noise/length/weight. Anything similar size should be the same. Rev9k can go shorter since its higher volume (more baffles too).
Id stay away from sub 5” 1.3” cans as all the tests ive seen were substantially louder.