The samurai has a 1.3l 8v engine thats weaker than the trackers. It has a solid axle up front with leaf springs all around.
The tracker, depending on the year, can have a 1.6l 8v, 1.6l 16v, and even bigger motors on the newer ones. They have a independent front suspension that uses struts. The rear uses coil springs.
Personally, I'd say get whatever you can find. The samurais are harder to find.