i would check out HID Hut for lightening needs ... they have a full array of MH HPS bulbs, hoods, etc.
I have had very good luck with Hydroponics, Grow Lights, Advanced Nutrients, Hydroponic Equipement, Indoor garden, Hydroponic Systems - Nanaimo Victoria BC Canada they sell lumatek digital balasts, I think they are the best on the market today. I have a 250w lumatek and complete with bulb and aircooled hood it was under 300 bucks. very very happy with the deal, the shipping was reasonable and fast. they ship descreet in plain brown boxes and they do ship to the USA
i would go with the 250. good price. not sure about quality i have never owned one . but this will handle up to 3 full sized plants very well. I know alot of the people on this site use htg and that cant be a bad thing.
glad i came across this! that answered my exact question! it seems you can get 250 at a good price and it should pack a punch!