At your age, you might not get a ton out of lower dosing. Your GH levels are already naturally high. For the guys that are 45, 50, they are going to get a nice boost out of 2-3iu becuase that will bring their declining levels back up. So for you, it might not be of great benefit. Some people, rare ones, do respond well to gh though and for these rare people, it can be a game changer. I would see how 4-6iu works for a long term program, at least 6 months. I dont really see any real world translation to these myths we hear. There are big guys on stage, but I believe it is due in large part to massive diets, lots of insulin and a lot more GH than we are talking about here. But really, even so, GH might not be as valuable of a tool to you unless you are aready pushing it. If you are getting ready for a National show in BB, then go for it, and make sure you use the best GH you can afford. Otherwise, I'd focus on what you can get out of AAS. Build solid cycles and work your ass off, eating and training hard. 

If you want to use GH, my thought would be to go with Hyge's or better. The Hyge kits are a little over dosed, so 4iu per day would be ok to start with. See how that goes, while on cycle with AAS.