I feel at this point I must recommend the movie "Lars and the real girl".
One man and his love doll goes dark comedy goes true romance flick.
Also the is an amazing book by photographer Elena Dorfman called Still Lovers which shows the complex relationships that some people have with their real dolls.
I believe the doll culture has gone beyond that of simply servicing a sexual need, some of these people are deeply in love with their silicone partners.
Also there is a wide range of porn featuring dolls, one in particular featuring Ron Jeremy.
..........as for the tattoo question, there is a guy in Texas who will airbrush your doll with any tattoo you like.
Theres also a really interesting documentary called "Guys and Dolls"
You can probably watch it online by now
Also , I'd like to point out, I do have a valid reason for knowing a lot about this subject!!!!
Honestly , i really do!