Not far from OT is the Brix bar in the Grand Hyatt on Scotts Road. I think it provides what you're looking for. I had stopped by there last time I was in town and it was quiet, but in retrospect I went much too early. I've read that peak time is 11:30 or so. The women there are a higher class and more expensive. I will be back in Singapore in May, on my way to Malaysia, and plan to check out Brix again. Action can also be found in the Clark Quay area, which has lots of bars and should also provide more conversational foreplay!