Coming from CFL's to HPS

Ok so iv been using cfl's for a while and there fine but i think im ready to make the jump to HPS. A place locally has a nice set up for $70. Its a 150w HPS how should I set it up? With CLF's i would have some tubes along the side and then a few 100w up top about 2 inches away from the plant. With HPS should I be that close or can I put it up at the top of my cabinet which is about 4' and let the plants come to the light. Also should I just use HPS for both flower and veg? Or to I need to get a MH to?

You could get 3 of these for that price and have triple the light if you are willing to do your own hood etc:
http://forums.slickdeals.net/showthread.php?t=1096767

Easily enough to grow several ounces. One 150w light alone I don't think is enough for most people to be satisfied but two or three can really grow some serious bud when used properly.

I would love to run a few of those but my houses power is out dated. I used to blow the breaker all the time with my cfl's so I think I'LL really be to run more than one. Iv got all the walls covered in mylar and its a smaller room. about 2 feet wide 1 foot deep and 4 feet tall.

I use 1 150w HPS with some CFL side lighting, just finished up my first grow, 700g wet weight, I will probably upgrade it to two lights this time, but for $20 a piece you can't beat it.

would i really need to make a shield for those or can i mount them to the bottom of a shelf and use mylar all around. Im still not sure hpw far to keep the plants from the light.

I keep my 150w HPS about 6 inches from the plants, I made a reflector for about $10.