A lot of people really think 4wd is necessary for average conditions, look at all the AWD Subarus running around! Truth be told common sense and conservative actions will keep you from getting stuck independant of how much traction your vehicle can provide.
A winch is 10x better than 4wd, simply because even with 4wd you can still get stuck, a ramp covered in ice is a good example, if all 4 tires are slipping you'll never make it up the ramp. With a winch you've got to be really stuck to make getting out impossible. Unfortuantely a WARN winch won't mount to the front of your truck, mounting kits are only available for 4x4 models, and only for Rangers as new as 2003. You may be able to find some kind of aftermarket or off brand winch mount for your truck though.
A winch is more of a lifetime investment, you can easily remove a winch from your truck and put it on a new truck in the future. There are Warn winches around that are nearly 30 years old and still being used.