Need something to tug the 850D around.  Got the rails cut/drilled/tapped tonight and got it in roller form:
Went with Russ's new airbag suspension.  Super nice stuff and makes it super easy to link up multiple axles.
Had the regular roadys so I was excited to see the wide guys come out:
Plan to try it 8x6 first, if needed I'll drop in a TLT up front.  Plan to use a Holmes Hobbies puller on either a 3-speed or an HD RC4WD R2 trans.  Been using their "Mega Truck" drivelines on the dump with no issues.  Pricey but they will hold up a good while.  Will eventually mod the body to a pete as well.  Still unsure on daycab/sleeper.