Great theme, kat!
I know you said to PM you about other media, but I'll ask this in the thread in case others are interested in the answer. How do you feel about white Signo Uni-ball gel pens? I often outline people in black, then the white gel pen, a technique I picked up from Amerasu. The ink is acid-free (I just checked), and the result looks like this. (Don't mind the scanner goo on the text. It didn't hurt the text, and I have since cleaned the bed.)