My goal is similar to yours, to gain strength and power and keep my weight at about 180lbs. Ive done alot of research into what supplements to take and its a really difficult decision to make when factoring in price per gram, price per serving, effectivness, taste etc. Alot of people will give alot of different advice (which will often contradict) and in the end youve just got to try a few different things and see what works for you. Heres what im taking at the moment and how i feel its working for me.
Glutamine Pills (1 a day) - Good for recovery and has worked well for me, also quite cheap.
Basic Whey protein (after workouts and first thing in morning) - Also good for recovery and is widely considered the best type of protein shake to buy.
Maxipower (30 mins before workout) - Supposed to help with power and give you energy to lift a higher weight and do more reps and sets. Only just started taking this, its very expensive, you get 16 servings for £40. Ive seen a slight change in performance the two times ive taken it and i seem to be recovering slightly quicker. personally i think its a bit expensive for what you get (also tastes vile)
Cytosport Muscle Milk (before bed) - Only just started takin this but it seems to really help recovery. Tastes better than most other protein shakes. Its O.K value, seems excellent as its £22 for 1125 gms but each serving is 75 gms so dont be fooled into thinking its extremly cheap.
Creatine - Im not taking this at the moment but im going to start when i finish my maxipower stuff. Controversal but is effective for gaining power and size. If your gunna get it id reconmend it in pill form but you can get it in shake form with a load of other ingriediants usually bunged in as well.
Anyway thats what im taking at the moment, hope it helps. (if anyone wishes to criticise the supplements i take and thinks im wasting my money, taking to much or not enough then feel free to do so, i might learn sumthin).