One of the many things to love about the P938, is it comes with nice sights, most models using SIG's Tritium nite sights. Most sights for the P series X-rays, Trijicon HDs etc, should fit as well, though for the ranges the gun would be normally used at and beyond, the stock sights seem just fine for me. If you change sights, note the numbers on your stock sights, "normal" for the P938 is #6 front and #8 rear.
As to action work and trigger pull reduction, SIG won't do that on the P938, but they will adjust it if it's out of spec I think (supposed to be 7.5 to 8.5 lbs). TheSigArmorer, will work on them, as I'm sure others will too.
I've written a number of posts re gunsmithing these guns you can google (P938, trigger, bumper) or add SigTalk to the search.
If your P938 is within pull spec, then it can be reduced further to around 5.5 lbs or so, by modifying the sear/ejector spring. You could insert the word "easy" in there somewhere, but the P938 is not as easy as the bigger SIG's to field strip IMO - or maybe I'm just klutzy. Edit - should have said detail strip, field stripping is easy once you get the hang of it, reassembling after a detail strip - I've done it 20 times, not bad, but not easy either.