Yeah, I think I'm going to get both systems and use them both for flowering all my future plants. Like bobber said, a 250w MH and a 400w HPS. And I'll just veg under the four 65w fluorex lights that are on their way now.
edit: actually this is where I'm torn. I would like to try the HID systems...but I would also like to try LED systems. Like...large scale LEDs. I just don't have the money to to both just to test them out for kicks. And of course, if the LEDs grow the plant very well, then I'd rather use those because they'll be more energy and heat efficient. AHHHH