Go with the DR-Z400SM and get the Avon Distanzia tires for it. That would most fit your 70% road / 30% offroad riding.
I have an SM, it’s a blast. Highway riding is no problem even when it’s stocked.
check out thumpertalk.com if you wanna learn more about the motards. they got experts for a lot bikes over there even DR-Zs and KTMs.