I order mine from GPZservices or WallMart depending on your state is required to sale you 30 pins. I do mine in my stomach all ready poking me enough IM that one less IM shot makes me happy, shoulders, traps, chest, upper quad are all good places to pin hgh im. Traps are actually very easy, shoulders i dont like cause if my chest is sore i have had it cramp while pinning and that sucks.
Slin pins are fine even if your not as lean just takes longer to absorb and spread some say that your wasting the gear which is bs. Slin pin you can get upto .5" in length which is more than enough for chest tri bi delt trap etc