10w30 around 5.5 quarts for the 4.0 engine.
Find a good performance shop around town, and get a good oil filter like a Bosch or WIX. Top off the oil level as needed after you run the Jeep engine 25 or so miles. (only if the engine needs it - check the dip stick while the engine is warm).
Same advice for the 2.5 Engine.