I have a Brooks B67 on my Ebike, a B17S on one of my folders and a Gyes "Brooks Swallow Clone" on my other folder. The B67 is definitely the way to go for an Ebike - I actually have mine mounted on a suspense seat post for "double-dampening" - great saddle and was instantly comfortable for me right out of the box.
The Gyes is also a very high quality saddle and if working on a budget a good option versus a Brooks.
Quick note - DO NOT over use proofhide, neatsfoot oil or any other saddle conditioners as it can weaken the leather over time! Just a little bit every few months should suffice and will result in a saddle that will outlive your bike!
1997 Gary Fisher HooKooEKoo Hard Tail MTB, 48V 1000W Yescom Rear Kit, 48V 15 AH Lifepo4 Sunthing28 Pack