You might already know this, but the Glock trigger will smooth up lots in the first few hundred rounds. Out of my three Glocks, the triggers with the most "rounds shot" are best.
The Glock trigger has almost 0.5" of take-up, and then it gets "stiff" and acts like a SA trigger. A broken-in Glock trigger should break pretty cleanly from this point. A dab of lube (CLP) in the right spot can make this nicer, once the parts are broken in.
For carry, I would absolutely use stock Glock parts. You can be assured that the factory parts are as reliable as your Glock will be -- they have been tested way, way, way more than any combination of aftermarket parts.
For example, many people replace their guiderods & springs with an aftermarket set and think nothing of it. I was extremely surprised to have my aftermarket guiderod break, rendering the pistol useless. That said, I do have an ISMI 20# spring on the stock glock plastic guiderod in my model 23/32.
If you want a target pistol or a race gun, a different platform may be a better choice...
-z