Changing Speaker setup in front doors Options

[Carnage]

I got a Celica St97 with the 6.5" speakers in the front doors.
I've heard that you can buy door panels from the GT-Four with setup
for 8", 4" and tweeters in the side mirror panels. I was thinking of buying
these door panels from my toyota shop, but do i need to do any convertions to fit
the 4" ?

[Carnage]

So there are 2 or 3 versions of the premium door panels?
A friend of mine who owned a GT-Four 96 told me that it came with
his car when he bought it. He's sold the car so i haven't seen the door
panels myself