Advice on 2008 3500 Cummins

Alrighty, well been a loyal ford owner for the past 14 years. Had a trusty 7.3 and loved it with minimal repair (basic maintenance and one injector), sold that and downgraded to an '04 5.4 3 valve and dealt with the spark plug and cam phaser problems-was not happy at all with that motor. really miss the diesel and now have a nice country home with property and actually have a legit reason to go back to a bigger truck. i've spent countless hrs researching the newer motors and all the issues surrounding the 6.0 and 6.4 powerstrokes have me looking at other badges. i'm currently looking at an '08 3500 mega cab laramie with the 6.7 cummins. it's got 160,000 ticks on the clock but they're throwing out what i consider a great price ($23,500) in this area (northwest ohio). it's a single wheel, loaded with navi and sunroof (yeah i know....) 4x4, black with tan interior, auto tranny and very, very clean. it's located at a small local dealer that has a great reputation for the trucks they sell. they specialize in used, higher mileage diesels so i know it's been gone through and detailed well. it has aftermarket tires on nitto grappler wheels, dpf delete with evi live tune (economy tune), spray in liner- all brand new done by the dealer.

my questions are what issues should i be worried about with these motors, i'm a ford guy so know nothing about current problems with the cummins, and if i do buy it what other mods should i look into? this truck will not be my daily driver, got a '98 4cyl subaru for that, and not looking for a race truck, got an '87 mustang and '79 trans am for that, just a reliable truck that will look good in my drive-way but also handle all the towing and hauling that i throw at it. i'm looking for economy mods that will stretch out the fuel i'll be putting in the tank.

i appreciate the help in advance, i learned a long time ago that forums are the absolute best places to go for help and advice. thanks again guys.