Everyone loves gear and it's easy to get carried away. Here is an old joke I read years ago:

Kid walks up to a champion motorcycle racer and asks "what can I add to my bike to make it go faster?" The champ looks at him and says "more gas."

Anyway, its a bad joke but kind of on point. Of the amps mentioned the only one I have experience with is the Katana and its great. But they probably all are in some way. Curious about blue tooth. The Kat does have an aux in if you want to hook your phone to it, or you can buy a bluetooth adapter for under $20. Doesn't do much except eliminate 1 more cable.

Good luck with whatever you decide.