I was just out through western Maryland and West Virgina on I70 and I68. It's very hilly and rt 40 runs next to them. So I'd think it could be a fun ride.
Not to far off I68 is the highest point in Pennsylvania, kind of disapointing but now I can say I was there
Ride out on rt. 40 and alt. 40 out to western, md. on a regular basis throughout the summer to visit the parents. Once you get out past sidling hill, rt.40 / rt.144 is pretty nice with loads of twist and turns. Through hagerstown area, etc. it's straight with rolling hills.
For the pa. area... near carlisle there is rt.74 which, north of Carlisle is pretty sweet. South of it is rolling hills. If you want some dirt / gravel then ridge road will take you clear from Carlisle out towards thurmont, md / carroll valley pa. where you could pick up rt. 16/116 to rt.30. Further south you have rt.616, 216 and 516...all farm country style highways with some twist (nothing special) but it is a fun and scenic route.
Rt.22, hwy.120, and rt.6, which is even further north, will offer a vast amount of scenery along with twist and turns, and swinging through little bodunk towns which is always fun to find the locals favorite ice cream parlor or food joint. And then in the far, north west corner of pa you have rt. 666, called the devils highway and for good reason. Some say this road is almost as technical, if not more so then the dragon. Can't say..haven't been on either, yet. One day. If it were me, I would head the northern route, skipping maryland and wv. almost altogether...head up towards the great lakes and what not while you're up that way. Plus if you take rt. 6 across pa, you have the option of seeing the pa version of the grand canyon and then hitting rt.666.
Hope this is of some help.