Help! I am about to pull my hair out!

My son has a 2011 KIA Optima SX with nav and the Infinty Premium sound package. He recently blew a front door speaker so now he wants to do a complete overhaul of his factory sound system. He isn’t looking to blow his trunk out with bass or anything, he is just wanting to replace the existing with upgraded equipment. I would imagine that his cars sound system was designed with the best size/type speakers to optimize the acoustics for the car so I am trying not to deviate from any of that but it is proving to be rather difficult. First off we are definitely on a budget. I don’t want to completely cheap out. I just want us to get the best bang for our buck. Second, there are a ton of different “known name” brands out there but I realize that every brand is going to have some duds so I know that we have to be very careful. Thirdly, I would like to keep all the equipment the same brand name if possible (it’s an OCD thing). Next, the spec sheet I found online shows the original speakers as such: Center of dash - (1) 4” Midrange, Corners of dash - (2) 4” 2-way midranges with a half inch tweeter, Front doors - (2) 6” Woofers, Rear doors - (2) 6” 2-way woofers with a half inch tweeter and Rear dash - (1) 8” Dual Voice Coil Subwoofer. I am extremely green when it comes to all of this. There is a lot of things AV that I am ignorant about like, what is the difference between a midrange speaker and a woofer? Also, since I am having such a hard time finding a 4” and a 6” (I know that the sizes will most likely be half of an inch to three quarters of an inch bigger on the after market speakers) midrange and/or woofer that I wonder if I could just buy a component speaker instead and just not use the tweeters that come with them? Should I just use 2-ways all around? Will that be too much high end and not enough midrange? Also, the spec sheet I found says that it is a 550 watts system? Does that mean the stereo is pushing the 550 watts or is there a factory amplifier? If there is should I replace that too?! I am in way over my head…. Thanks for reading all of this. Any help at all would be greatly appreciated.

My son has a 2011 KIA Optima SX with nav and the Infinty Premium sound package. He recently blew a front door speaker so now he wants to do a complete overhaul of his factory sound system. He isn’t looking to blow his trunk out with bass or anything, he is just wanting to replace the existing with upgraded equipment. I would imagine that his cars sound system was designed with the best size/type speakers to optimize the acoustics for the car so I am trying not to deviate from any of that but it is proving to be rather difficult. First off we are definitely on a budget. I don’t want to completely cheap out. I just want us to get the best bang for our buck. Second, there are a ton of different “known name” brands out there but I realize that every brand is going to have some duds so I know that we have to be very careful. Thirdly, I would like to keep all the equipment the same brand name if possible (it’s an OCD thing). Next, the spec sheet I found online shows the original speakers as such: Center of dash - (1) 4” Midrange, Corners of dash - (2) 4” 2-way midranges with a half inch tweeter, Front doors - (2) 6” Woofers, Rear doors - (2) 6” 2-way woofers with a half inch tweeter and Rear dash - (1) 8” Dual Voice Coil Subwoofer. I am extremely green when it comes to all of this. There is a lot of things AV that I am ignorant about like, what is the difference between a midrange speaker and a woofer? Also, since I am having such a hard time finding a 4” and a 6” (I know that the sizes will most likely be half of an inch to three quarters of an inch bigger on the after market speakers) midrange and/or woofer that I wonder if I could just buy a component speaker instead and just not use the tweeters that come with them? Should I just use 2-ways all around? Will that be too much high end and not enough midrange? Also, the spec sheet I found says that it is a 550 watts system? Does that mean the stereo is pushing the 550 watts or is there a factory amplifier? If there is should I replace that too?! I am in way over my head…. Thanks for reading all of this. Any help at all would be greatly appreciated.