I haven't done this but to get the more upright position one could use a stem extender, perhaps in combination with an adjustable stem. Also, perhaps, a drop-bar with shallower drop? Deluxe option would be a custom stem though that's about $200-$300.
Nothing wrong with converting to moustache/flat bar of course but new brakes & shifters might cost more. OTOH some advantages to the flat bar switch--that gives access to wider variety of drivetrain & brake options.