I have a M&P 9C with the APEX trigger, and let me tell you - it is a dream. I've posted this in other threads, but here you go. I got the following parts:
DC/AEK spring kit, mainly to set the spring to a decent weight for carry. Probably lighter than your compliant trigger, not sure if there's a law against it where you are.
RAM (reset assist module), to make the reset more distinct.
Machined Sear and Striker Block, to make the trigger pull smooth instead of gritty.
AEK Trigger, because the hinged safety sucks.
To install the AEK trigger you might need to do some modification to the transfer bar (it's pretty simple though, just using a flathead to expand the loop), and most of these parts will require you to be able to punch pins out and back in. That's the extent of it. Most people can DIY with this kit, there's even youtube videos by APEX that show you how to do them.
Personally, I tend to miss pins, which resulted in me needing a gunsmith, but I'm pretty sure 90% of the population that is mentally competent to handle firearms should be capable of doing the kit themselves.