If it were me......
Starting with the tractor:
Pick your favorite truck, stretch the frame....plenty of "how to's"out there...your going to have to scratch build the toter home portion. The link below is for a smaller trailer than you want, but shows some of the scratch building involved with the truck and trailer.
https://www.modeltruckbuilder.com/index.php?/forums/topic/518-ford-aeromax-120-rv-conversion-and-custom-galaxie-enclosed-trailer/&tab=comments#comment-3267 You can spread the axles,run triple axles, etc. with the NASCAR trailers, again by stretching the frame. If it where me, I would go this route. Plenty of after market available as far as a trailer suspension goes if you wanting to run spread axles, triple axles, air ride, etc. etc. I thick it would be easier to convert one of these trailers from an 80's/90's NASCAR style to something modern like your after.
Another possibility would be the AMT Lowboy trailer, you would still have a fair amount of scratch building, but its already a triple axle, with a drop deck
https://www.modeltruckbuilder.com/index.php?/forums/topic/98-redesigned-amt-lowboy-trailer/&tab=comments#comment-704
I
think this builder used the AMT lowboy trailer, or possibly an another after market lowboy trailer for this build
https://www.modeltruckbuilder.com/index.php?/gallery/image/56-v-gaines-racing-transport/ I am having real good luck as of late sourcing truck parts and pieces from Shapeways, seen a lot of trailers there as well.