''The Enforcer 160 shoots a 20 inch, 400 grain carbon arrow at 300+ feet per second, generating 85 foot-pounds of kinetic energy.''
You could shoot either.
The Parker arrows that came with one of my crossbows weigh in at 298, minus tip. So a 100 gr tip will get you very close to 400 gr. The 125 gr tip will get you 422, about ideal for your bow. The heavier arrow will impart less stress on bow, give you tad more kinetic energy but you will lose a few fps and slightly higher trajectory.
For comparison I shoot the 445 gr in my Cyclone at 355 fps.