Howdy!
cuchulainn - the truck is lookin' good! I bought this kit like two years ago, don't know when I'm going to build it. But I have an idea, maybe you'll find it interesting - there are many Italeri kits that have prety nice Freightliner chassis - for one there is that quite nice Freightliner conventional - worth having on its own - but for example all the truck models trying to pass for a Mack Superliner - they have actually a Freightliner chassis, with long frame (over 250 inches 1:1), air ride, turbocharged Cummins diesel and Fuller gearbox - wouldn't that make a nice kitbash? I have to add the Italeri chassis also has front axle with positionable front wheels.
Hope it helps, I'm going to build it this way someday. Thanks for reading, have a nice day
Paweł