You could go Kawai VPC-1 which is just the controller, and then connect it via MIDI to whatever you like. That way, you get a wooden action without paying for the sound engine (I've got my VCP-1 connected to a CP Reface):
I looked up the VPC-1 and while I probably would pay a bit more just to have speakers and a sound engine - the weight difference is interesting. It's 29.5kg for the VPC-1 vs. 17.0kg for the ES920!
The VPC-1's weight is, from what I can tell, reasonable given the action it uses. Its bizarrely named "RM3II action" is much closer to the Grand Feel action they put in their high-end digital uprights than to normal portable digital piano actions. Also, the ES920 is significantly lighter than its competitors.
I looked up the VPC-1 and while I probably would pay a bit more just to have speakers and a sound engine - the weight difference is interesting. It's 29.5kg for the VPC-1 vs. 17.0kg for the ES920!