Customizing my CA M15A4 blowback?!

Hi this is my first post BTW (:

i have an CA M15A4 blow back i want to costumize i really want to put on these part:

http://www.airsoftpost.com/matrix-sr25-type-conversion-m4m16-series-airsoft-p-30549.html
http://www.airsoftpost.com/sr25-type-airsoft-mock-suppressor-barrel-extension-sr25-series-airsoft-p-29755.html
http://www.airsoftpost.com/matrix-harris-style-spring-eject-socom-sniper-bipod-adapter-clip-p-28965.html
http://www.airsoftpost.com/classic-army-matrix-king-arms-tactical-vertical-support-hand-grip-black-p-27228.html
http://www.airsoftpost.com/king-arms-matrix-dbali-type-peq2-mount-battery-with-108v-battery-pack-p-29718.html
And a Sniper scope??

I want to know do i need a new inner barrel for the Sr-25 kit ??? if i do what inner barrel should i then buy ?

It looks like your just focusing on externals. You may want to get a longer inner barrel. Don't get a 6.01 tightbore, something like a 6.03.

Well...Wait what FPS does your gun shoot at now?

I think its 350 fps

I just want to know what inner barrel i need

How long is the SR25 barrel kit?

i have found out what inner barrel i need thanks.... BTW its a 509mm 6.003