Stopping for 24 hours on the way is considered a stop-over. Typically the lowest fares do not allow stop-overs so that will increase price along with the added expense of hotels, food etc.

Depending on the length of the stop, the airline will or will not check the bag all the way through to the destination.

Here's a flexible dates search on Kayak from Chicago to Abu Dhabi

http://www.kayak.com/flights/ord-AUH...02-25-flexible

Flights on multiple airlines are about $900 RT. Lufthansa may work keeping flights around 9 hours or less with a few hours between flights