You would need a better amp to support all of the speakers. The base amp is hardly OK for the speakers it supports already. Hooking 2 more subs up will make it sound TERRIBLE. That, plus the wiring.
I did a full premium conversion on my old 2014. It will cost you $2,500-$3,000 depending on the deals you can find and such.
The brushed aluminum dash panels costed me about $300
I wired up my own LEDs for like $30 (footwells)
I snatched up the premium door panels for like $500 I believe. And I wired the LEDs in the door handle on them so they worked.
Premium cluster I got for $150 shipped. Then $150 for the Ford VCM Tool. $50 for the steering wheel buttons.
Leather Seat covers for $600
Leather E Brake for $40
MyColor cup holder for $80
Shaker Radio Faceplate for $50
MyColor Door Sills for $80
Brushed Aluminum sport pedals for $50
Then whatever pricing you can find to redo the sound system.
I might be missing stuff but that should give a rough idea.
The items to be careful with is doing the Cluster swap, wiring the Door sills, and removing the dash panel on the passenger side to the airbag.
I say be careful with the door sills because if you tap into the wrong wire, you can blow the fuse to your car's security system. And the car may not want to start anymore until you replace the fuse. lol (ask me how I know!)
All of that pricing was based on what I found 2 years ago. You might find stuff for cheaper now. Just depends. Ebay will be one of your best friends.
Here are some pics of my final stage with my "Base" Model 2014.
I did remove a few...performance parts from it before these pics.