Maybe he is already at his potential? Not everybody can just get big naturally.
But you are asking a very broad question about what gear to take, etc. Especially without relating to us your goals, age, length of time you have trained, etc.
Do some searches on eq(equibolan/boldenone), test (testosterone/sust/omna), winny (winstrol/stanazolol), dbol (methandrostenolone/dianabol), deca (deca-durabolin/nandrolone). Also do a search for clomid, arimidex, liquidex, and proviron.
Those should get you started, and may turn you on to new ones. But these are typically used for beginners, Not that you will never use them again, just that a typical beginner stack consists of 2 injectibles and 1 oral.
This is a great chance for you to find out what you want. After you find a few, and think you know what kind of cycle, post what you think. Then guys like ultra, and mustang with tweak it for you to get the most out of it.