I-90 through Chicago is shorter, but the traffic can be significantly worse. You say Friday night, but how late? 5PM I'd do 294 every time. Later would get better. Definitely check the traffic when you pickup the car.
There are no tolls on 90 from O'Hare into downtown, but then there are tolls on 90 after it splits from 94 south of downtown, first as the Chicago Skyway, then as the Indiana toll road. 94 remains free but is a little bit longer (though not enough longer that I ever take 90 going to Indiana if I'm not going somewhere right off 90 before they meet again).
The flight doesn't arrive until 11pm. So I'd say about midnight.
I'm heading to Elkhart, Indiana