There are a LOT of FB sneaker groups in Singapore! You can't find them by searching in FB because they are closed groups. The only way you can join is when you're added and vouched by a member of the group.
Flyknit Racer black/white isn't available anymore, bro. Sold out a long time ago.
You can check out other colorways though. Check out shops like i-Run and Limited Edt. See the first page of this thread for details.