For the sake of others who might be interested to know I shall answer my own question You can find the whole range of RSL birdies at Queensway. Less the Classic tourneys. I did not seem to see them there.
RSL number one (Gold packaging) is I think the highest end RSL shuttles you can get in Singapore. I get mine from Gala, the price there is the most competitive.
There are 4 shop, Bedok North St 2 #01-40, near bedok sports hall Tampines telepark #01-19, near tampines sports hall Jurong East Sports and Cultural Centre #03-04 The new outlet is at sengkang, near the sengkang sports hall. The one i visited is at bedok, they have the stock but not sure abt other branch
I tested RSL Classic(Speed 77) and APACS AERO-FLIGHT 700(Speed 77). Still prefer APACS AERO-FLIGHT 700 in durability and dropping point and the cost is reasonable at S$24.
I used to get Gala...but recently their price for RSL also increase alot...cannot discount much also unless u buy a lot....now i buy from Chau Beng on 2nd Floor....cheaper by abt $2 if pay by cash