Well at 145lbs I think you should hold off on taking any type of AAS until
1. you pack on more size naturally
2. do alot more research on what your about to put into your body.
Right now FOOD is your best friend. Make sure your eating enough total cals a day and aim for at least 1.5grams of protein per pound of body weight. Train hard and heavy and all those combined should get your weight up. If you need any further help feel free to contact me via PM or e-mail
M18