As far as a compensator, you would most likely need to get an aftermarket extended barrel. Extended barrels come in both threaded and non-threaded styles, compensators come threaded with a locking set screw on the bottom side. They can be found as well as a magwell, can be found around the glock parts supplier sites (glockworx.com, rockyourglock.com, glockstore.com, glockworld.com, glockmeister.com or even midwayusa.com).
A great trigger job will take about an hour. There are two parts to this. As for part one, its called the 25 cent trigger job. You will need a Scherer (or your choice of brand) 3.5lb connector, polish compound, a dremel w/ polish pad for faster polishing, pin punch or GLOCK takedown tool, your favorite gun oil and a Q-tip. Look up the 25 cent trigger job on youtube and then oil the metal friction services up with the Q-tip and thats done.
As far as the second part goes, its what I like to call "Advanced GLOCK Trigger Job". I am currently working on making a video explaining the process and the whats needed to do it here in a day or two.