I agree about the Pensylvania Turnpike. I can't believe that they have the nerve to charge people to drive on that road.
You don't say what part of Illinois you will be leaving from, but if I-70 looks like the best route to you, I would recommend it for the first part of your route. You have two pretty good options in eastern Ohio/western Pensylvania:
1. You could cut south in eastern Ohio on I-77 and pick up US-50 at Parkersburg, WV, and go east on US-50. We drive this road with a trailer every year from Cincinnati to Washington. It's an excellent road and the scenery is nice. Then, near Clarksburg, WV, take I-79 north to meet I-68 near Morgantown.
2. Alternatively, you could continueon I-70 to I-79 in western Pensylvania and take it south to get onto I-68 at Morgantown, WV. This would probably be a bit shorter for you.
In either case, I recommend using I-68 across northern Maryland, rather than the Pensylvania Turnpike. This is basically the same recommendation as Larry's. I strongly second his opinion.
As an aside, Baltimore is not far from Sparks, MD, the home of Rickson Truck Accessories. They fixed me up with wheels the last time I was out there. Their service is great.
Happy motoring.
Loren