To answer your question, you can find one online either ebay or other toyota sites like TTORA.com. The front diff is the same used on tacomas of the same year.
The usual seems to be the shifting rod getting stuck within the actuator. Some have tapped the actuator to engage. If you remove it, you may have to add some grease to the shifting rod. Since the shifting rod is not fully engaging, the 4HI will blink. 4Lo will blink because 4Hi is not engaged. You have to engage 4Hi before you can engage 4Lo.