No. Just street vendors selling regular stuff. You can buy everything from underwear to cars from street vendors.
There's plenty of info here and elsewhere about the girls.
My first girl was at a place called Takara in Patpong. It's a massage parlor, so no barfine. A fishbowl of sorts, pick a girl, make a deal (I said 2000 LT, she wanted more, I stayed at 2000, she smiled and said OK) pay and go. Ignore the touts at the bottom of the stairs; they'll grab your arm and pretend that they brought you there for a commission, just tell mamasan "no tout" or "no guide" or something so that she knows that you came by yourself. There are maps of Patpong, Nana Plaza and Soi Cowboy in many places, perhaps here, but google: patpong map or Nana map...
MBK http://en.wikipedia.org/wiki/MBK_Center
Erawan Museum http://en.wikipedia.org/wiki/Erawan_Museum
Silom is a neighborhood on Silom Rd., sometimes referred to as the Silom/Sathorn or Bangrak neighborhood. It's very close to Lumpini Park. The BTS runs overhead on Silom. On Sukhumvit, near Nana Plaza, I felt that I had to keep my guard up, for good reason. Near Soi Cowboy not so much, but even less on Silom.
If you can, download a taxi card from your hotel's website. Even better if it's got Thai instructions. Use it at the airport to get to your hotel and mamasan may ask for it too, but you should get a taxi card at hotel check in too.