Replacing JBL system in 2005

So I’m trying to find out how to properly replace the JBL system in my new to me 2005 Prius. It already has an aftermarket touch screen head unit but I want to replace all the speakers, amp, and add a subwoofer.

At least one (probably 2+) of the JBLs are blown and so it needs to be done. The issue I’ve run into is the tech at crutchfield told me the car’s electrical system can only handle up to a 30 amp audio system. So he sent me some recommendations, but I’m just wondering if there is any wiggle room with that 30 amp max? Has anyone else done this job and have any speaker recommendations?
I’ve heard replacing the JBL system has its difficulties for some reason so I’d be happy to hear any warnings, tips and tricks.