Back in the 2013 the Shimano Alfine series would be your best bet if you wanted Hydraulic Disc Brakes and Di2. They feature high braking power ideal for cyclocross and on-road riding, ergonomic hood and lever design and the reservoir tank provides pad clearance auto-adjust to maintain consistent pad clearance. You can adjust both the lever reach and free stroke.
Each of these shifter has one e-Tube port and a pair of shifters weighs about 500g.
They do not have the 'hidden' button on top of the hoods that the other modern shift levers do.
From CarltonBale.com:
These are compatible with the SM-RT99 centerlock 140mm and 160mm rotors and WH-RX31 wheelset (which as no standard rim brake track.) These require the BR-785 dual piston hydraulic disc calipers. They do not have the special wiring port required for the SW-R610 Sprint Shifters and a SM-EW90-B 5-port junction A is required to use the SW-R600 climbing shifter.
Modern Di2 shift levers have buttons on top of the hoods, but unless you're on 12-speed Di2, their default function only works with a wireless unit or d-fly. Learn how to set these buttons to shift derailleurs.
Learn how to install Di2 drop bar levers commonly used on Di2 road bikes or Di2 gravel bikes. I'll walk you through the process and give you some useful tips.
Do you have small hands? Or extra large hands? Read this page to figure out how to change your Shimano Di2 shift lever (or shifter) reach.
Below is an overview of all known firmware updates for this component. The changelog texts are Shimano's, and quite often they're a bit cryptic - sorry!
3.1.0
Additional ANT function for D-FLY channel switch setting (cycle computer setting)
3.0.0
Adjust compatibility
2.2.0
Improving usability of data uploading
