Just to add my 2 cents of experience in a recent trip.
Geylang;

Geylang: thais S$80 Ma Lam like
Chinese on street as early as 9am, didn't try.
Sauna in commercial bldg next to Orchard Hotel good hardware, Had malaysian chinese, pretty acceptable damage S$210.

Freelance: well known webasites, similar operation to hotel 141 but communicate by sms in Eng.
Good quality Thais, had one that offered backdoor. Damage S$150.

Info as mentioned above.
Geylang is close to MRT. Around Lor 10-18 will ahve lots of girls. The streets are behand Sims Avenue. Just get a tourist map or ask the hotel & you will get direction.

For FL, just check websites & contact them by SMS.