Upgraded from G2 to a GX7

Decided to upgrade my camera body this week and got a GX7 which came with the 20mm prime and the 13-32 by redemption.
Ive recently let my 14-42 go with the G2 body and am left with my 45-200 and 100-300.

So my question is what is the best lens combos to go with to cover the 13-300 range im working in.
Do Olympus 4/3 lenses fit direct to the panasonic mount.
Im thinking of keeping the 20mm prime as its a great low light lens.
Was thinking of selling the 45-200 and getting a Panasonic 14-140 lens, but is there a better olympus lens to cover this range.
Also keeping the 100-300 as its a great lens, but will have to see how it handles/performs on the smaller GX body.