Noob looking at a "New" truck

Hello everyone, and thank you for making such a great community. I am looking at an '03 3500HD LT crew cab, 4x4, DRW. The truck has 219000 miles. It is a repo with some cosmetic damage. (Fiberglass fenders need replaced, bumper, mirrors, and is NASTY.) I'm OK with all that, but I'm not going to have any maintenance records, so I have to decide if it is mechanically sound. I'm going over the "Read before posting" post in order to make me a checklist of things to check. The injectors appear to be the biggest issues. Does anyone have any additional suggestions to look for?

I have an el cheapo ODB II code scanner that I can take with me. Will it work with these trucks and will it tell me anything interesting?

KBB is 15700 in fair condition. Right now I think it is in a little worse than fair. What would you offer if it is sound?

Thank you in advance!

Aaron