Called QR UK, waited for a bit and got STPC for my R class both way.
(PSA-DOH-HND) ~13hrs and ~19hrs.
WOW this will be my first time on Qatar and also for such a long transit.
Hopefully this will be smooth and pleasant.

Do I need to prepare some Qatari Rial for my transit? Credit card good enough?(For example only plan to stay in the provided hotel and if there is availability for the free local tour)