Ive learnt that there are different types of muscle and yu can have big huge muscles, that is only good for explosive power, then yu can have that big strong muscle that will give you retarded amounts of stamina and power, but u wont be agile.You can have a mix of those muscle, probably wont LOOK as impressive as just straight up MASS but u will probably appreciate your body more if you choose which type/types you want to develop.
As for supplimentation, the fitness store in long circular is great, that guy has great products as well as great advice.