the best thing u can take at your age and weight is food, food, and more food! 150 lbs is way too small to take steroids. You need to build a solid foundation first, otherwise u wont get much from them and keep even less. Steroids arent miracle drugs that will get u big and ripped in no time. It requires a lot of dedication as well as solid training and an excellent diet. Which is obvious you dont have based on your stats. Sounds to me like your just looking for a shortcut, that is the wrong way to go. Eat like its suggested in this thread:
http://forums.steroid.com/showthread.php?t=113010
After u read that, eat like that every day for a couple more years and watch the size come in no time. After that you can look into steroids b/c w/out a solid knowledge of how to eat properly you wont get crap from steroids