Re: My Son\'s Tracker
If your son is interested in off-roading, I can't stress enough that you find a club near you that he can join. The places we can wheel are diminishing and teaching the new generation the right way and place to wheel is important.
I'm more of a Samurai/Jeep guy myself, but it sounds like you're on the right track. I've found that I can go nearly anywhere with a 3" lift and 31" tires on my Cherokee. This is on mild/moderate and a few hard trails. So a mild lift and decent tires should be good for your son.
Keep the lift mild (under 3 inches combined) and the tires under 30, and you'll have a stout little off-roader. I would put skid plates up on your list because it will protect the vehicle from expensive repairs while your son is learning to drive and off-road. Once your boy has experience driving on the road, and off-roading, step him up to a rear or front locker.
An inexpensive way to get the lift would be coil spring spacers and a body lift. I would discuss this idea more, with people who actually wheel the Sidekick.
For tires I would choose one of the mud or all terrain tires. If you choose mud tires have them siped down the center. This will make the tire better handling on wet pavement. I run BFG AT's on my Cherokee, and Swamper TSL Radials on my Samurai. The AT's do a good enough job off-road and are much better on road. Their biggest failing is in the mud, but they've given great traction on rocks, dirt, hills, and sand.
Teaching him to drive the Tracker on the road is going to be the harder of the two styles of driving. He needs to learn right up front that the Tracker is not a sports car, and doesn't handle like one. Without much driving experience, and being a teenage boy, he'll want to push the thing to it's limits. That, of course, is where accidents and roll overs occur. I would probably put a sticker on the center of his dash that says "SPEED KILLS" as a reminder that he receives every time he gets in the truck.
Good luck with your project. It would be helpfull if you filled in your profile and let us know where you're from. You'll find this forum to be a valuable resource and find many people here willing to help.