Gas M9 Chamber?

Okay guys, sorry for another post, but again with my upgrading question series.

So I have a KJW M9 Tac Master.
What i plan to do with it, was to change the outer barrel, so it could have a 14mm positive threading.
I plan to get this one

http://www.airsoftpost.com/matrix-steel-threaded-barrel-marui-bell-series-airsoft-blowback-included-p-28512.html

Then I plan to use this Barrel Extenstion.

http://www.airsoftpost.com/matrix-stubby-mock-airsoft-suppressor-clockwise-p-28508.html

Now I have a easier question because it has two answers that I don't know.

The easier question to answer: Where can I get a inner barrel, and a chamber to put in my KJW M9 Tac Master's Outer Barrel.

If that fails,
The harder question to answer is: How can I take off the chamber that is connected to the outerbarrel and how do i take out the inner barrel?

EDIT PLEASE READ
I found an inner barrel.
http://www.airsoftpost.com/601mm-tight-bore-inner-barrel-hicapa-series-inch-p-31236.html
its for a Tokyo Mauri Hi-Capa.
But my question was would it fit inside the outer barrel of my gun? Or does it NEED a Hi-capa?
Just to note, I don't mind if it extends out of the outerbarrel, infact thats a want for me.
Because I'm putting a barrel extention over it.