I am no expert, and I have not been at this long, but I have lost just over 30 pounds in about nine weeks. I think that the biggest thing by far is the number of calories you consume and how much water you drink. I use a calorie counter on my iPhone, and I have not cheated once. I also drink about 1.5 gallons of water a day, and try to eat 5-6 times a day. Aside from that and exercise, I think that multivitamins are a good start. Whey protein is not going to help or really hurt in terms of loosing weight. It helps you get protein, while reducing the amount of calories that you would otherwise get in "real" food. I would strongly suggest that you be very careful with any sort of stimulant or thermogenic supplement. If you are eating properly and exercising, you will not need anything else. If you are hell bent on taking something, then I would suggest that you look into b-complex vitamins and vitamin c. The stimulants, diuretics, thermogenics, etc. are generally caffeine based, with b vitamins. Caffeine is counter productive to healthy weight loss and metabolism. B vitamins will give you an added boost, and are safe, as they are water soluble. Most stuff at GNC is overpriced and are not needed. Whey protein is a good idea, but just remember that those are extra calories that you will have to account for if watching your diet. Prework outs, testosterone boosters, diet pills, and the like are really just marketing gimmicks. Try them if you like, but I would first commend you for your progress, and then suggest you take a look at a calorie counting program and give that a try. Drink lots of water, too. Peace & good luck.
Don't believe anything you read on the net. Except this. Well, including this, I suppose.