I'm not 100% sure but I don't think the eBay guy is the guy who built that truck.
Here's the original build and I think he sold it:
http://www.ratrodsrule.com/forum/showthread.php?t=22220
The plans are for 2x4 and that truck was built with 2x3 I think.
I haven't read this whole build thread in a while, but you might want to go through it to be sure it's the actual builder who's selling the plans.