Is the older say 99" XLT 4x4 w/"offroad" package basically the same as a say 04" FX4 on the newer models? Just a different name? I did a search but no real clear answer really.

 

No. Offroad and pre 04 FX4 were a package that was added to the vehicle. Included thing like skid plates, different shocks, etc. The 04 up FX4 is now a model, just like XLT, XL etc. It is far more than the package that used to be added on.