Schlumpf 2022 Build Questions

Looking for advice for brake set for G36.
I am anticipating riding my new (to be built g36) in high 20’S low 30s’s on roads so am asking for advice for a decent hydraulic brake set.
Recently I have been enjoying hill climbing and downhill runs around Sydney… Bobbin Head, Berowra Waters… Galton Gorge this weekend. Typically they are 3 - 4km climbs then 3 - 4km downhills (x2 times for session) average grade 6-8%. I would like to do these routes on the G36.
Main intended use of G36 is commuting. Currently on KH36, I average 15kph (max) for 15km route according to Wahoo computer with speed sensor. Max speed is 23kph. On a 1km straight on road next to rowing course I can maintain 23kph (x 6 runs in session) the standard brakes on the KH36 seem ok for stopping. Not sure if they actually over heat.

Do I need 4 piston brakes on the G36? What is the best (less expensive) 2 piston brake?
I’m looking at getting vcx cranks 100/125/150… set to 150 for learning, 125 when proficient and have the possibility of 100 to keep my options open (may not be possible strength / torque wise, but worth a try)