a good MR expert would sandwich a good PY or J deal out of SIN during those 8 days
Do watch out for the rain season in DPS, and maybe try out some other destinations closer if you do not want to do another 2 hours on separate tickets. There is also interesting places to go like Royal Brunei offers BKK/SIN-BWN-HKG in J on 787 for 300s one way, with stopover in Brunei. And you can do EK J HKG-BKK on the big boy 388 for the cheap as well. It is a good region to try out tons of nice products.
Also for crediting AS, it has to be SQ metal and SQ coded flight, but ticket stock can be anything.