If you reckon that you'll be flying QR more than CX/KA, then I would have thought it'd make sense for you to go with QR - unless of course you want to earn miles on work travel and use them on short-haul holiday hops (in which case Asia Miles would make sense; but I've not looked into how many Qmiles (?) you need for a KA or CX shorthaul flight and how that'd compare to earn-rates and burn-rates on CX/KA)