Dash 2.6" Upgrade Suggestions

My Current setup is a bit of an older JVC Double-Din unit. My car has JBL amp and I am using it. My front 6x9s are unplugged since they're bypassed and I have a Rockford punch 12 sub for that. I'll probably unplug the rear 6.5" too.

I'm wondering suggestions for great mid and high? To my they already sound pretty darn good but once I get rather high in volume I get some distortion. I don't want them to make any bass so I"m worried that 3.5" speakers would attempt to create more bass.

I've read dash speakers get roughly measured 15rms so should I shoot for a 20rms 3.5"?

Can I bridge the 6x9s into the dash speakers which others have done to get more power to the dash speakers? I have a basic understand on this but would like to learn more thank you!