You have a 400HPS already? The other stuff isn't going to do much except generate heat and suck up power. If you're looking to add more light, without destroying your finances with an HPS or MH, try this:

I took a few of those 24" cool florourscent lights, and mounted them on the walls sideways in my grow room (attached). They'll make a pretty good dent as far as lights go, and I like them because they get into the lower regions that the HPS doesn't get down to because of shadows and leaf penetration.