protein drinks and weight gain drinks

[slim]

Need some advice on these drinks. I was just at the supplement store and guy recommended I take a preworkout Creatine drink called Superpump250. I was looking at the pamphlet he gave me and it shows a pics of 2 guys who took one dose of this preworkout and they took pics b4 and after the workout and u can see an incredible difference. So much so that I am obviously skeptical. It also says in the pamphlet that they did a study with placebo drinks and those who got the placebo had a 3.5% increase in lean muscle mass of the arms and those who took superpump250 gained 9%.

Anyways, he suggested I take Creatine preworkout and a protein drink right after. I ended up buying just the protein drink called Iso Flex bc it tasted good and I wanted to make sure I keep on this stuff.

A little about me. I'm 38 and 6ft tall but only 163 lbs. I want to weigh about 175 to 180lbs. I joined the gym 5 weeks ago and have been going about 5-6 times a week including cardio about 3 times a week. I would definitley consider myself a hard gainer.

1) Do I really need the Creatine preworkout? If so what is the best one....and it HAS to taste decent.
2) Is the IsoFlex that I bought any good?
3) Does brand matter? I mean if there are 2 products and they both have the same amount of protein per scoop, is there any diff which I buy?

Remember, I'm not looking to be a bodybuilder or anything so an extra gram of protein here or there isn't the end of the world for me. I just want something that tastes good and is not expensive. BTW I paid 42 bucks for the 2 lbs bucket of Iso Flex. Im sure I can get it cheaper online or something. Any recommendations on where to get this stuff cheap. I live in Toronto.