depending on amount of volume even 1/2" 28/29g will work for site pins in bis, tris, delts, even subQ.. 25g 1 to 1.5" would be good alternative also or if you shop around online a few place have 27g in 1" and 1.5"... my reason for advocating smaller pins is simply the accumulation of scar tissue etc that can build up over the years if you plan on being in the game for a while..
I know i got areas of my quads of accumulated scar tissue from all the ED tren ace years ago that snap and crackle when pinned now along with small patches of spider veins due to associated trauma to tissue. they're more noticeable when I'm pasty tho..