Only the Ogre came builtup, all other surly bikes (Troll, BridgeClub) were frameset only.
The Ogre is not an ebike yet and is using the stock tektro brakes.
All bikes are using 180mm front rotor and 160mm rear rotor.
Both the Troll and Bridgeclub(both 52V BBSHD at 1500W) are using Deore 2 piston calibers front/back with resin pads. I got these on sale for a significant discount at the end of last year when the new models were coming out. I initially planned on going to better pads and/or larger 200mm rotor but the stock resin pads and 180mm rotor work fine on these bikes. I can easily get the back wheel off the ground (stoppies) when stopping. I practice max braking at least once per ride to keep my skills/reaction up to date most of the time starting from 30+mph. I see no reason to upgrade anything unless I plan on doing alot more downhills.
FWIW, I have been MTBing since the early 90s including lots of downhill courses at ski resorts and am very familiar with the need for good brakes,