Your number of options is relative to the amount of work you're willing to do. If you want to drop in a complete engine, then a 01 FFV engine from a Ranger or Mazda b3000 is your best bet. If you're willing to do some work, then you have many more options. The 3.0 Vulcan motor was used in many different vehicles for over 20 years. They can be found in Rangers/ b3000, Taurus/Sable, Tempo/Topaz, Probe, and Aerostar models. The long blocks for these engines are interchangeable, so you have many options for potential donors, that are typically easier to find, and cheaper to buy.
A FWD donor would require you to swap your oil pan, upper and lower intake manifolds, exhaust, and all of your electronics.
A RWD donor (depending on year) may only require you to swap your sensors/electronics.
Engines from 01 and newer will be the easiest to swap, but will also be the most expensive. Just depends what your priorities are. Basically, any 3.0 OHV motor can work with a bit of parts swapping, but there are to many small things to list without knowing the year/model of the donor vehicle.