Most of the J-women you see in Singapore will be wifes of bankers, or tourists. I guess if you wanted to try your nanpa skills, go to Orchard Road cafes and shopping mall.
On Orchard Road itself is the famous 4 Floors Of Whores Orchard Towers. The only bar there really worth hanging in is Ipanema which got good live music. Beer is cheaper b4 10 PM. Most of the girls are from Vietnam and Thailand and dont come cheap, 400 SGD for LT but you can knock them down to 200 as time gets l8
For cheap ST get MTR to Kalang or Aljunied stations and walk to the Lorongs (small streets or sois) off Geylang Road. Not as good as it used to be due to police crackdowns. You will find really hot Chinese girls on Tamla Road for 100 SGD ST but not all will go with whities unless you speak some Mandarin. Indonesians are 70/80 (whitey rate, locals pay half) and you can get Thais for 60. All stand by the side of the road. They will take u to a design8d ST hotel which is another 10 SGD. You will get 30 minutes max. There are also walk-in Thai fishbowl joints which cost 80 (again, a whitey rate but u get 40 minits instead of 20 minits).
Duxton Road gotta lotta Flippa hostess bars. The girls are not supposed to go with customers but some do. U mite get a BJ if you buy the most expensive lady drink but it depends on the bar
Singapore is apparently the most expensive city in the world now. Sounds like the OP wont need to pay for a hotel but if u r a tourist, u cn save dosh by eating at hawkers food courts and staying in the Geylang area I mentioned which is also convenient for the airport
Enjoy