The Shadow 2 shares some parts with the SP-01, but not all.
Matching the recoil spring setup to your ammunition can reduce felt recoil to improve accuracy and speed.
Softer springs reduce trigger weight.
A very soft hammer spring may require a softer firing pin spring or extended firing pin to maintain reliability.
Single action triggers are adjustable to minimize pre-travel at the expense of the double action capability.
Short reset disconnectors do the same while retaining the double action capability, but is not adjustable.
Competition hammers have shallower hooks, reducing creep and allowing for a nice crisp break.
Changing the controls can tailor the pistol to your hand size and grip.
Magazine wells normally work in conjunction with shorter grips and different mag bases.
Magazine bases for Shadow magazines.
Some popular upgrades to cure reliability issues.
Popular upgrades for IPSC Standard Division.
Not many options here.
Most improvements are designed to make the gun easier to shoot.