If you don't think you will need to modify either vehicle to meet your requirements, get the Sidekick. The fuel injected 1.6L is more powerful, reliable, and gets as good or better fuel mileage than the 1.3L that came in the Samurai. Most of the 1.3's were carburated. Also the Sidekick will ride better, is more aerodynamic, and has a higher top speed.
If you were wanting lift, big tires, gears, and lockers, I would say get the Samurai. I am on my 4 Samurai, and they are loads of fun.
