1000w MH lighting for flower???advice +rep

Hey whats good guys i was fortunate enough to receive a 1000w mh ballast and socket set...freebie...i need to purchase a bulb though..all good...anyhow I've got two questions for you guys ...1 can i use a 400 to 600 watt bulb instead of the full 1000w???? and second is what type of differences will I see between MH and HPS for flower if any...thanks in advance guys and gals....since the ballast was a freebie and new i wouldn't mind trying to get use out of it...other than just vegging with it...cheers

you have a 1000 watt MH ballast, you MUST use a 1000 watt bulb...PERIOD

MH is considered best for veg since blue spectrum

HPS considered best for flowering since red spectrum

You could get a conversion bulb for flowering and use same ballast

im no expert but i heard when you flower with mh bulb you get quality shit just nott alot