Hey I'm 18 and about 5 1/2 inch length erect and I'm really interested in the pumps. I'm really new to this so I have a few questions. Which cheap pump would work best and what size tube would I need? And do pumps have permanent improvements or are they temporary? And if they are temporary then how long does it last until I'm back to my regular size? Oh and I will be jelqing as well so that I can get some growth. Thanks!