-https://en.wikipedia.org/wiki/Anabolism
If what they say is in the bottle is actually in the bottle, then no you won't need to take PCT supplements. Like Hyde said, it you gain 8-15 lbs off of a bottle or two of HICA and Epicat, you would have eventually gained that naturally anyway.
As far as gaining 8-10 additional pounds each cycle/compound, it doesn't work that way. Take for instance a guy who runs a 12 week test/deca cycle. He may gain 20-25 lbs. Now, if he were to add 2 more compounds to the mix or even 4 more compounds to the mix, he would not see increases in weight of 40-60 lbs. There will always be a point in time when the gains diminish (the point of diminishing return) and you will have to fight to put on weight. The genetic make-up of each individual will help to determine that. There are guys on hear that run steroids all year round and maintain basically the same weight.
You sound young. My advice to you would be to train naturally for as long as you possibly can before you start wasting money on supplements that you don't need. Spend your money on food, protein powder and creatine (if you want). Diet and training will always be more important than gear or 'natural' supplements in a bottle. Not to mention, this is a really expensive lifestyle to maintain.