couple of questions, just bought a 600watt hps for 150 off craigslist

Ok im going to put my grow up prolly tomorrow or maybe even moday, ill post pics etc, Just bought this 600watt hps kit for $150 was it a good buy? so the ballast read 600watt the bulb reads 400 watts philips hps, so he sold me a 400watt bulb no biggie i tend to replace it with a brand new 600 watt hopefully 600watt mh then switch it to a hps, comes with a white hood with a glass piece of the light, has to holes for air cooling , A was it a good buy and B is it cool to use 400 watts?. i might just use a 400watt mh for my veg, less money on energy bill and less heat issues. the guy told me I dont need to use special bulbs to switch between hps and mh, but who knows, Im going to start with a soil grow, for my first harvest ever, then do both, a soil on one side and a hydro on the other side, might do the drip system, but anways WEEEEEEE I get to grow now weeeeeeeeeeeeeeeeeeee lol,

the hood is all white, i see hoods with foil inside, should i do this aswell?

not really sure about using a 400w ina 600w set up call the hydro store they will know for sure no guessing.and hps is def better for flowering def switch em out after done veggin, also me and many others prefer flouros or cfl,s for veg.been veggin over 2 yrs with t 12 now tryin to switch to t5 way cheaper to run and guys at hydro said t5 are better than mh.

I was also thinking, if the socket right now is holding a 400watt hps and my ballast is 600watt can i put a 600watt into that socket??

A 400watt bulb will not work with that ballast,you need a 600watt bulb.I would buy the hps and use cfl for vegging because of cost.Although if you not worried about elect. cost you can veg very nice plants with the hps.The first 2 weeks i would go cfl or a shop light.Yes that was a great buy! Good Luck!!