Here's my take.
A 3.0 in a 2wd that you'd tow with every once in a while would be a good setup. A 3.0 kinda sucks as a 4x4 engine without steep gearing. If you want just a commuter that'd see a few bags of dirt, or a table, etc, every once in a while an N/A 2.3/5 Lima or 2.3 Duratech would be my choice.
A 4.0 OHV is a better choice for a 4x4, and/or for a truck that'll see alot of towing. See, it's not how much torque the OHV make vs. the 3.0......It's the RPM at which it makes it. Seeing as the OHV isn't made anymore......the SOHC 4.0 would be substituted.
Now, a 5.0 swap? Heavy, big, 8 cylinders, worse fuel mileage, etc. Bah.....would be cool but not worth it in my opinion.
A 2.3 Turbo swap is what's on my mind right now. Using a small iHi turbo on a basic stock turbo setup.....I'd make enough torque when needed to tow(of coarse I'd have a big A$$ radiator to keep it cool under boost), or plow through snow drifts, and still have a 4 cylinder displacement to get the 20+ mpg on a regular basis while cruising the interstate or highways. The 2.3 also has a big aftermarket........see why it's so appealing?
Having heard opinions on, and driven quite a few of, ALL engine swaps and ALL stock engines......that's my opinion.