The more time you have, the better! 6 West through Hawley,Pa and as far west as you can take it.
I had six days to ride in May of "08". This road is loaded with 70/80mph sweepers with police substations
hundreds of miles apart. Totally silent stretches of empty road for miles and miles.I went into western Ohio
via some of the finest back roads on earth. Eastern Ohio through E. Canton and Berlin is a MUST! Central
to Western Ohio has a bunch of crazy long straights. Maybe Consider Ohio Bike Week!! Great Riding from the EAST.

 

I love on Route 6 (AKA: Main St) in western PA. It's a nice road to get some country mountain turns. As for the police presence.. they're mostly concerned with speed limits inside of town. Watch those sudden 35mph's and you're golden.

 

Last week I rode Cincinnati to Montreal, QB. I crossed PA on Rt6. It's as you describe. A good run. I used Rt7 and 100 in Vermont, also good stuff. On return I came thru Lake Placid, NY area on 9N and 86, maybe my favorite scenery the whole trip and neat road too. Ironman was going on that weekend. Rt 3 thru the Adirondacks was a good mix of sweepers and rolling hills. Superslab to Niagara then blast home.