Big request here, not expecting anything just throwing it out there.
The operator of the most E170/75s is Republic Airways who operates for the three legacy carriers in the US.
Types and Airlines:
Delta: E170, E75S
United: E170, E75L
American: E75S, E75L
(keep in mind I did not fact check this, this is just what I currently know of)
The difference between the E75S and E75L is the winglets; E75S has standard ones and the E75L has the enhanced ones.
FeelThere does not have an E75S model, so the closest we have is an E170.
Currently there are only two Republic repaints I am aware of: the United E75L by inibuilds and the Delta E170 (which also covers the E75S) by Jeffrey Bryner.
So, for the request part, I think a United E170 and American E75S (E170 model) and E75L (E175 model) would fit these aircraft very nicely.
Again, not expecting anything but simply thinking out loud.