150W HPS can get you 2 zips(if you take common sense in there with ya).
I don't suggest going hydro to begin unless your a chemist or something similar. Its nothing personal but hydro is step 3 on the herb growing difficulty meter. step 1 being soil, step 2 being a soiless mix, then step 3 hydro. If you've got a really green thumb and good knowledge of hydroponics you could try hydro first, but I wouldn't.
I do use the sun visor as a reflector for my CFL's but I wouldn't do it on my HPS(too hot).