Some questions for those familiar/experienced with light or other SAD therapy

I've suffered from SAD as well as delayed sleep phase syndrome for as long as I can remember and have been on every medication under the sun to no benefit but for whatever reason had never heard of light therapy or the other non-pharmaceutical treatments for SAD/DSPS until just recently after seeing a new doctor. He told me that light boxes, dawn simulators and negative ion generators could all greatly help relieve me of my seasonal depression as well as reverse my DSPS. The SAD is really my main concern; I live in northern Maine where it gets particularly bleak and depressing in peak winter and is pretty dark and cold from early September to late April (aka 2/3rds of the year). The seasons are changing earlier this year and some rather depressing events have happened in my personal life lately so I'm dreading the fall and winter much more than usual...somehow I can sense that it's going to take a much harsher toll on me this year.

I've used the sun and warmth of the summer to my advantage and have found that getting out as much as possible on sunny, warm days is incredibly helpful, but those days are very quickly fading now, thus my high interest in light therapy. I'm a broke 20-year-old and this stuff isn't cheap but it's certainly less expensive than an 8 month getaway trip to southern California to escape the symptoms. As for the DSPS, it's a year-round thing that I've learned to live with, but life would definitely be easier if I could fall asleep before 3 or 4AM or wake up before noon.
Anyway, I've done a fair amount of research on the SAD treatment therapies but am still new to it and have some questions about treatment that I was hoping could be answered by those more knowledgeable on the topic(s).

1. Between blue light, full spectrum light and green light, which would be the best choice? I've read that blue light is the most effective treatment-wise but also that it's more dangerous since its shorter wavelengths have the potential to damage the retina. However, I'm not sure how much truth there is to either claim.

2. All of the instructions I've read for light therapy devices involve using it for only brief 15 - 60 minute periods in the morning after waking up. Would there be any harm in using it for longer than that, or even all day as a consistent light source? I'm often in the same spot in the same room for the majority of the day either at home or at work (in front of a computer in both cases) and I'm wondering what potential harm (or benefit) there would be in just leaving it to the side turned on while I'm there.

3. Sort of expanding on the last question, does anyone have any experience with or know anything about using lighting similar to that found in therapeutic light boxes in fixed/steady light sources like lightbulbs in overhead fixtures or desk lamps/floor lamps? I was wondering about the possibility of replacing my lightbulbs with full spectrum bulbs manufactured by the same companies that make therapy light boxes, such as Sun-A-Lux/Sunwave or Full Spectrum Solutions/BlueMax. The problem I can foresee with those however is that they may provide too much daylight and have no dimming feature which could be a bad thing late at night when trying to get to sleep, which is why I was also considering a dimmable desk or floor lamp with light therapy qualities and capacities like the kind on the BlueMax site or the Desklamp sold here on the Lumie site. I haven't found a whole lot of testimonials or reviews on this kind of steady lighting though, and I'm also not sure if they would be a suitable replacement for a light box or would work in addition to one of them, which is why I was hoping someone here might know more.

4. Speaking of things I haven't found a lot of reviews or testimonials for, does anyone here have any experience with or knowledge about high-density negative air ionization for SAD? I'm specifically wondering exactly how the devices are used...i.e. only for short periods, only during certain times of the day or left running 24/7. There are only two negative ion generator products I've found so far that have any customer reviews, the first being the Wein VI-2500 and the second being the NatureBright SunTouch Plus (which serves as a light box as well). I'm unsure of which would be more effective; I've found several sites that emphasize that there needs to be a high flow rate for it to be effective and I'm having a hard time telling which of the two measures higher in that regard.

5. Finally, for those who have used them, does anyone here have any recommendations for dawn simulators? What’s worked? What hasn’t? So far every dawn simulator I’ve found has had a fair amount of critical reviews or hasn’t had any reviews at all so I’m looking for experiences from real people about what has been most effective for them—in fact, that goes for anything/everything else, too, not just dawn simulation clocks.

Thanks in advance for any and all help!

Sorry forgot to mention that whilst using a lightbox, you don't need to stare into the light. It just needs to be positioned so that the light is shining into your eyes so you can watch tv and read in front of it. Some people may experience headache especially if using alot so maybe a good idea to use the time advised by manufacturers until you get used to it and then maybe use for longer building up.