As Neowulf has stated above, a PC version of the game doesn't exist. There are there possibilities.
1. No work has been done on a PC version and a PC version is several months away.
2. A PC version DOES exist and rockstar games simply wanted to build up anticipation.
3. A PC version will never come. Much like how Grand Theft Advanced was not released for PC.
I suspect option 1 or 3 is most likely true. If so, then theres always Saints Row or Sleeping Dogs(Set in Hong Kong).