Why would you want to replace either? Five and a half pounds with a two stage break so you know exactly when its going to go bang seems about right on an SD gun. As far as the barrel? What is wrong with it? The bullet comes out, goes where I want it to, and has done so thousands of times on three different 9mm Glocks. To me, a guy who modifies a Glock's trigger or barrel is either running in rarefied circles of competition, or is just flat bored with more money than sense. Leave the damn thing alone, it will shoot just fine. If you must fiddle with it, put some tritium sights on it or replace the guide rod with a laser. Beyond that, its just fine out of the box. If you want to buy a gun that you have to mess with five minutes after you take it home, buy a rust bucket.
FQ13
All my Glock barrels are stock, but if you want to shoot lead bullets and keep the fouling to a less totally unacceptable level (any level of lead fouling is unacceptable to me..don't touch lead bullets) or want to reload the 40S&W extensively, you would be interested in a replacement barrel.
My triggers are OEM, but I have stoned the burrs and rough surfaces and have a much smoother trigger pull. Swapping connectors, I can go from the standard trigger pull to a 2.5 lb pull and back in a few minutes.
It would be nice if Glock did offer the replacement barrels as an option. Would consider one if it was tennifer treated.
Another reason to equip an aftermarket barrel is that bullets shot through an aftermarket barrel can not be traced to your gun with the OEM barrel with matching serial numbers installed. If your lifestyle might include a need for that.