Gr16 CQW Rush Barrel

[ST3W1E]

Hi, I'm still relatively new to airsoft but I have decided to delve into modifying the innards of my Gr16.
I'm thinking of replacing the stock 230mm barrel with a longer tight bore barrel for the added accuracy but needed some advice on what would be compatible, some links to barrels that fit would be great.
I would then also want to screw on a mock suppressor to shroud any protruding barrel, again any links to a suppressor and barrel combo would be amazing.

Any advice appreciated.