Purchasing first truck, need opinions pl

Hi im looking at purchasing a used semi for hauling grain. Dont have oil samples or engine history, just dynos. Heres my options...2007 century with detroit 14L, 3.58 rears, 22.5 drives, 10 speed, 634,000 miles, 429 hp, 4"blowby, 50 psi oil pressure, 36lbs boost... Next is 2006 columbia with almost exact same specs and dyno as the o7 century but has 793,000miles. Last is 2007 t600 with c15 accert, 3.25 rears, 22.5 drives, 13 speed. It has 442hp, 5"blowby, 44lbs boost, and 70 psi oil pressure, with 900,000 miles. So the question is, which truck would you choose? I like the t600 the most but the miles scare me. Any input or opinions would be much appreciated.

 

Local

 

Off Farm, granaries, etc.

 

Ive been looking for a 03 or earlier for several months now and have not found anything that wasnt wore out or sold before i could go look at it. Theres been a few good ones here and there but they dont last long.

 

Dont have anymore time left to look, harvest is almost here