Great choice!
I broke in my P99 9mm with 124gr Geco FMJ ($6.95/50). Lately I've been using Wally World Winchester 115gr FMJ (100/box @$10.xx), only because it's a roadtrip for me to get the Geco.
For economic reasons, I don't shoot too many Hydra-Shoks, but have run a box through.
I believe the general consensus is to use about 300-400 rounds of the heavier 124gr for break-in.
I still need to try out some RNL, since our indoor range allows Lead Only (weak back stop), and one more snow storm will force me indoors.