For the Lunchbox, DEFINITELY consider purchasing the ballbearings. I am not sure if they make such an impact in terms of ride and performance, but they should in terms of longevity, especially considering that they are an optional replacement for the plastic bushings in the gearbox.
If you ever upgrade to a more powerful motor, you will need to consider making sure you have ballbearings in your gearbox and not the plastic bushings which wear out a lot sooner. If you buy the ball bearings before you build the van, you will save yourself the hassle of rebuilding the gearbox in order to replace with those ball bearings.
I noticed that with ball bearings, if you spin your wheels, they keep spinning and when they finally lose momentum, they start rolling in the opposite direction. With plastic bushings, you get some spin but obviously a lot more resistance.
Ball bearings (full set for the Lunchbox) will cost you as low as $5.50, as it did for me through an ebay seller.
I do recommend oil filled shocks. The size for them are 85mm or 80mm (eye to eye, not full length) for the rear, and 80mm or 75mm (again eye-to-eye length)for the front shocks.
The stock pogosticks on the Lunchbox make a lot of chassis noise due to its design. They are not bad. But a stiffer suspension should make the LB handle much better, a lot quieter, and funner to drive especially on jumps.
I purchased 4 shocks for $10.56.
For durability and maintenance stuff, know that for the LB the parts that are bound to break are the plastic body mounts and the wire springs.
A great mod for the body mounts, is to purchase aluminum mounts for the Tamiya F1 and then buy small l brackets at a hardware store to fit them onto your LB. This, as it turns out, is a great solution considering that aluminum mounts mounted directly to the LB break the chassis itself on a hard impact. Here's a video about it:http://www.youtube.com/watch?v=bAY99..._order&list=UL
For the wiresprings, the simplest thing to do is to be creative with a metal clothes hanger. I have that setup. It's not pretty but it works fine.
Finally, know that the part that will get the most and obvious damage is the body. So consider getting a lexan body instead.
The Lunchbox is a great truck and fun to drive - and fast if you want it to be. With a better motor, however, it requires an experienced driver.
You and your son will love it. Great in the snow and fun if you have an empty soda can or two for your LB to kick around.