Tink's data search turns up quite a bit about Mrs. le Mar: she's a French socialite with an enormous trust fund formerly married to an equally-rich aristocrat. Since her divorce, she's turned her resources to "making the Matrix a safer place". It's your standard "Protect the Children" rhetoric tinged with an unmistakeable sense that she thinks she knows better than everyone else how they should live. She's made outreaches to several megacorps about supporting stricter Matrix laws which, of course, they have been all too eager to agree with. She seems like an average aristocrat with too much money and time on her hands looking for something to keep her occupied.
Draco and Shark, however, hear quite a different story from the shadows. The way their contacts tell it le Mar is a pawn of the Corporate Court, a proxy they can use to "independently" protest for more authority over the Matrix. She considers shadowrunners to be lowbrow scum beneath her attention and has a particular hatred for heavily-cybered individuals. However, lately she's been hiring runners to investigate dead zones and other sites with unusual or absent Matrix architecture.
As for Three Star, his contact Lang
does know of a few things that fit the bill: atropine, cyanide, or, if he's feeling creative, nova scorpion venom. Atropine has legitimate medical uses and is the easiest to get; the other two are illegal.
I'm just going to cheat and stick the information everyone obtained into one post, so there 
. As for Diego, the availability and cost of his special orders are on page 84 of arsenal. Fang could obtain them for him with the normal contact rules or he could try to get them himself.
