hey Glamis (do we share the same hobby? ; sand?)
sounds like you are heading in the right direction (truck conversion, big cat, autoshift,..) if you pull heavy toys.
in my (personal
) opinion the only thing i dont like on that rig you posted is the freightshaker cab. somehow everything (mainly the dash) looks "cheap" and "tacky".
i would recomend you to take a look inside a KW T2000 (or a Pete
)
for used trucks check out
Truckpaper
hope that helps