Wolff will sell you a trigger spring and a hammer spring. Replacement is pretty easy. However, my suggestion is to shoot it for a while to get used to it first. Then you can always change the springs out later.
My favorite revolver holster is the Bianchi 111 Cyclone. DeSantis also makes a good holster and the Triple K Lightning is also good.
As far as accessories, I prefer Pachmayr finger groove grips over the Hogues that Ruger supplies. Hogue also makes wood finger groove grips for the GP100 series.
Oh, yeah, pick up a couple of speedloaders and practice with them.
“If ye love wealth better than liberty, the tranquility of servitude better than the animating contest of freedom, go home from us in peace. We ask not your counsels or arms. Crouch down and lick the hands which feed you. May your chains set lightly upon you, and may posterity forget that ye were our countrymen.” ― Samuel Adams