You might take a look at the Trek FX series. The 7.1 and 7.2 have a "stagger" frame that might help (http://www.trekbikes.com/au/en/bikes...x/7_2_fx_wsd/#). Not technically a road bike, but probably alot more nimble than what you have. The only other new option I see is to build up a SOMA Buena Vista mixte frame (http://velotraffic.com/2010/06/best-mixte-bikes-2010/). This would probably be a budget buster but would allow you to choose exactly how you want it built. The link shows a bunch of available mixte bikes for you to take a look at. There is also the used market for mixte or step through road frames. They would probably end up a pretty pricey project too.
Good luck in your search,
P2
2018 Trek Silque SLR6 - Selle SMP Glider
2018 Specialized Dolce EVO Comp - Selle SMP Glider
2011 Trek Madone 5.2 WSD -Selle SMP Glider
2013 Giant TCX W - Oura 143