Wow those UBid toys are very cool looking... I built a couple of semi logging trucks, man it had to be around 10 years ago, I think the plans were in wood mag, was very fun and it was cool to see the kids faces light up when I gave them to them.
Try http://www.toysandjoys.com/ They have an extensive list of trucks, cars, planes, and trains. Different size patterns, you may want to order a catalog. I used a couple of their paterns a few years ago. They are pretty good. Some of the patterns are pretty detailed.
If you want quick, cheap & simple look in my album for examples. These are mostly cutoff toys from glued up scrap. I got a bag of wheels & axles from http://www.meiselwoodhobby.com/
because I couldn't find them anyplace else.
Here's a link to the truck plans from wood mag. I built a few of these, I would consider them somewhat on the easy scale because there is no real detail to deal with. But were fun to make and really liked to see the kids face light up when I gave them to them, thats what I remember the most