I know that you asked about Olympus bodies, but you definitely don't want to dismiss Panasonic bodies either. Take a look at the
Panasonic G85. It might be a tad bit bigger than a similar Olympus body, but it has the swivel screen, 5-axis IBIS, takes 4K video, weather sealed, vibration free shutter, & does a lot of other stuff. There's even an optional battery grip for it as well. It offers a ton of bang for the buck value.
The only Olympus body that I would consider is the OMD E-M5II, but I'd definitely take the G85 over that.