yea wear long sleeves but at the place my dad works, lockheed martin, they actually are going to seminars and stuff about how they have to basically ignore piercings and/or tattoos. like any negative feelings they have about them they have to suck it up and live with it, and accept the fact that some of the people they hire, esp. the younger ones, have tattoos and stuff. they dont care if you have a tattoo on your head.. if you're  smart and best for the job they'd hire you.
diversity matters a LOT to the company. but i guess a lot of other companies arent like that.
anyway, go for the long sleeved shirt.