IMO, 5w-30 fully synthetic engine oil, from any of Shell, Total, Kixx, Caltex / Havoline, or even PSO, should work fine.
If it does not suit, and / or you face high oil consumption issues (or bluish smoke from the exhaust) then from next time, use 10w-30 by Caltex / Havoline.
If it also does not suit, and / or you face high oil consumption issues (or bluish smoke from the exhaust) then from next time, use 10w-40 fully synthetic engine oil by ZIC.
(Although in your case, I would sincerely recommend that you start in the reverse order, and not make straight jump from 20w-50 to 5w-30, rather in gradual steps, i.e. 1st 10w-40, then 10w-30, and lastly, 5w-30, and then finalise the grade which suits the best!
)