Question on Volvos 06 and later

Hope you guys don't mind me posting here, if you do, I'll deal with the flames.
I'm retired US Army, disabled and can no longer operate a vehicle with a clutch. I'm looking at getting a large 5th wheel and a Volvo class 8 to tow it, just feel better having the power and brakes to haul 21k and up. My intent since I'm retired is to travel around the country until my health prohibits and then decide what I intend to do.
I'm looking at purchasing an 06 Volvo 780, 760k miles, VED12 engine with ultra shift transmission. The dealer is asking 37k, truck is in pretty good shape, some dings, cracks in windshield, but they'll fix those. My intent is to have an oil test done, if that's good then get a dyno run. Any thoughts on the particular year of truck, no def but will have an EGR I would guess. I'm going to assume my mileage will be around 10 - 14k a year.
Would I be better off getting and 07 or later with the DEF? I know there is a lot of discussion about auto shift trans, but I have no choice but to use one.
I've thought about saving more money and getting a newer truck with an ishift, but most of those are in the 60k and up range. Any other thoughts on whether I would be better off with a much newer trucks, say 08 or later?
Thanks for any thoughts or help.
John

 

Interesting replies, appreciate the info, lots of things I had not considered.
As far as the 670, is there any real difference between the 670 and 770/780 other then sleeper size? There is an 04 for sale with 860k miles, with a freedom line for 16k, with an ISX, is that too many miles, would getting an overhead on it realistically extend the engine life? It does have an air slide, which I know I can sell to the local dealer as he as already told me that he's always on the lookout for one.
http://www.truckpaper.com/listingsdetail/detail.aspx?OHID=3308310
Thanks for taking the time to help me out, really appreciate it.
John

 

"Yep" yep too many miles, or yep its a good deal?

 

Thank You
John