I've set up Cura 2.5 as a Prusa I3, but didn't have a problem with Mirrored prints.
I did forget to change the bed size, and last night lost the edge of a large print. You need to change:
Settings, Printer, Manage Printers, Anet A8 (I renamed mine to this), and then set X,Y,Z to 220, 220, 240. Nozzle size is 0.4
Everything else leave as is. I've not changed any of the standard Gcode.