Hello Snowball,

Like they said before it doesn't matter which, and HPS can be used from start to finish.
I'll go one further and say they will probably do better with the HPS.
I just switched out a 600wMH conversion bulb used in my mom room for a 600 watt HPS because I decided to try out some auto-flowers for shits and giggles. Plus went from 24/0 to 20/4 to make the autos real happy, and the moms and transplants don't seem to mind at all either.

good luck with your grow