Scooby1991

So I want to run a full decat system on my blobeye wrx but unsure of what pipes I need to purchase, I'm wanting it to be fully decatted from the turbo. I know what cat back I'm after it's just all the pipe work after that. Also once is has a full decat system on it will it need to be remapped? I've currently got the PPP on my car & a k&n panel filter. Will I be able to tell a good difference from the map with a full decat system, uprated fuel pump & panel filter on, or should I wait untill I've collected the following parts....
Sti 550 injectors
3Port boost solenoid
Sti tmic with undertray
Uprated fuel pump
Full decat system
Td05 turbo upgrade as oppose to my current td04
Panel filter
I think that's it unless I missed something. Last question once I've installed all the following will this see me to around 340-350 bhp.

Any advice & help appreciated