aP
I am using Chris King R45 disc hubs, which are available with a Campagnolo freehub body. The disc version is 135mm space on the rear.
Other than these, you could use DT240s, which aren’t available with a Campagnolo freehub body as standard, but can be swapped over with a couple of 5mm allen keys and 1 minute of time. The freehubs are common between their road and off-road hubs.
I run SR EPS with BB7 SLs. Having just waited 5 months from the official announcement of the new battery to actually getting one in my grubby mitts, since there hasn’t been anything official about EPS Hydro just yet, I wouldn’t bother waiting!
I suspect the world and standards will have moved on before Campagnolo come to the party, given that both of their main competitors are already there and eating all of the cake!