first build in a looong time first simi

[AK Lonewolf]

I finally pulled the trigger and bought a king hauler Icouldn't make up my mind globe or king was I going to build a straight dump truck or tractor trailer
still a little up in the air I really would like to do a side dump or belly but might be a little bit out of my comfort zone on the first build I may just build a kit end dump trailer
the one thing I do know is that I want to stretch it not sure how long ordered blank frame rails 36 in.
any and all thoughts and suggestions welcome should get the kit on the 23rd :
anyone know where to find pre cut trailer frame rails to scale?