We do Lowe's (by day) and run Amazon by night
Personally I'm partial to older International trucks....(I recently drove a newer Penske International truck when one of our trucks was down but while very nice ...... It would be cost prohibitive and I would hate to think how many $$ fixing a new one would be or could be...
I like the large step out (easy to step on to get out of the truck fuel tanks of the older Top Kicks (I have a 1994) but the Cat engine is $$ to have a dealer tinker with (doing the 3116 injectors and setting the racks is big $$).
My ideal truck would be a 1996 International (newest one with all mechanical DT 466 (simple / cheap to fix / and older if maintained means less property taxes ) , Twin large fuel tanks ( my 1999 truck has 1 small tank on the drivers side and one large on the passenger side and if you sit on the side hill too long (or road for that matter), fuel transfers from the little tank to the bigger one and you can end up running out of fuel because mine seems to suck from the small one first until the tanks equalize .....2 large tanks is better (more range and offsets the fuel transfer issue....like my 2001 truck) or 1 large tank is second best (but less range before having to fuel up).
I like 26' boxes, 102 wide and standard tall height with translucent roof....more room to move in and roof lets light in so it doesn't feel like a cave....24' will work with Lowe's deliveries but 26' and wide helps with Amazon because they like to fill you up and their pallets are not always stacked neatly so the wider body is helpful
1 row of E track is nice but the more the merrier.
Ideally get a tuck under liftgate / Ramp combination if possible .... Tuck under is easy to dock with (for doing freight) and can move appliances in tight areas....If acting as a moving co , ramps work well / better if space permits.
I'd stay under 26K and with auto tranny so truck is more easily used by all.
Airbrakes are nice (although more maintenance points than simple juice brakes) BUT for hard core appliance delivery I wished my trucks were airbraked since my drivers probably don't chock wheels all the time ( without air brakes or manual trannies, the only thing holding back the truck from rolling in an older international truck with auto tranny (no park pin) is the cable brake and if the cable brakes and the wheels are not chocked bad things will happen....
NOTE: one of my is trucks is equipped with a pull out knob that locks the hydraulic brakes....THAT is good but not all juice braked trucks have that feature.....It may be difficult / costly to add on afterwards.
Although I haven't seriously looked into it, I had / have considered using super singles on my trucks only because where I live dual wheeled vehicles are not allowed on city streets between midnight and 6 am or they are subject to ticketing....Running amazon at night took care of that issue for me since my trucks are gone overnight otherwise I would have to revisit the super single option (I don't want to pay to park my trucks and prefer to have them close to home so I can work on them etc....yeah neighbors love me.
Freightliners are OK and they can have the great cummins engines but older internationals are far easier to get parts for in general so I stuck with 1985 - 2001 internationals....
Anyways just my opinion....Hope it helps you and good luck in your search
the cats unless you got deep pockets(and mine are so deep I cant find any money) 5.9 over the 6.7...Other than that I'm all over the place, I am targeting around 20K for a truck, if I could get it done with peace of mind for 12-15 that would be ideal. Steer me in the right direction and I'll tell you how to make the best old fashioned' your side of the border.