What is the best way to use Qantas points to fly from Brisbane to London in business class?

Hi, my husband and I have 350K+ Qantas points but will have quite a few more after our trip to the USA in a couple of weeks time. We have never booked a flight using rewards and are having trouble negotiating the best way to do so. We want to fly return to London in April 2019 in business class, no set dates, we are flexible. We live near Brisbane but are happy to fly to another capital city to start the journey. Can I ask for help on the best route/airline/use of points from the community please.
Thanks, Ruth.

PS Brisbane Australia


BNE-DXB-LHR with Emirates would cost 128k Qantas pts in business class.

BNE-HKG-LHR with Cathay Pacific would cost 139k Qantas pts in business class.

Emirates tax portion generally costs more.