I firmly believe that multiple small lamps are better than 1000s, unless you're growing in a freaking BARN with multiple 1000's!

You are going to save yourself a bit of a headache using 4x600 because you will be able to arrange them in such a way as to get a nice even distribution of light throughout the room, without risk of serious hot spots.

And you have the flexibility of when you are just starting out and only have enough plants to justify turning on one of the 600s, you aren't wasting energy.

HOWEVER:
Have you ever grown before?

Starting small is wise. If this is your first time around, I'd say go for 1x250 or 400 MH + 1x600HPS, MH for veg, HPS for flower. See how it goes. Add lights as needed.

Best of luck.