30 day juice fast?

Because my eating habits have been pretty awful, and I've been drinking too much, I feel it is time for a good detox. I feel I would also benefit from a spiritual boost that would come from a fast. So far, I have only had experience with Water Fasts less than a week, but I am considering a 30-day juice fast once I get my hands on a juicer. How many of you have done this successfully, and what fruits/vegetables do you feel are absolutely necessary. I'm 24 years old with no history of serious (physical) illness; I do have clinical depression, but the sites I've read up on about juice fasting seem to state that Depression is a good reason to fast rather a reason not to fast.

I am not underweight, so I have no concerns about dropping too low should I lose weight during the fast; in fact, I am about 15-20 pounds overweight so that would not exactly be bad. However, I have no intention of purposely losing weight by fasting; I would simply not mind if it came off. On a related note, though, I heard that juice fasting detox can help skin regain elasticity. I have lost 140 pounds. Will this help me with loose skin? I don't have much, thanks to weight training, but any help in that department would be great.

Should I use a nutrition tracker to make sure I get what I need and adjust what fruits/vegetables I use accordingly? Will psyllium be necessary to prevent constipation or will the vegetables do that job or should I resort to herbal laxatives such as dandelion tea or strawberry greens? How hard is it to regain a good metabolism after a fast? I do intend to work out, as I have always done, since next semester will be starting, and I gain free access to a gym starting June 30th.