Oh boy...
That is one of the most opined subjects you can get into with a crowd like this.
Ok I'll just say, I use Mobile 1 Turbo Diesel Truck 5w/40.
It's reasonably priced.
It's easily available.
It's on sale usually a couple of times per year.
It easily exceeds the requirements of the 2.8L CRD
However, there are others that also do the same, and of course, "availability and price may vary".
All my previous turbo diesels I used Delo 400 15w/40, and it never let me down. That said, factory specs for this little gem calls for pure synthetic cj-4 or better, and I don't find the price difference (over time) enough to justify using Delo over Mobile, Shell, or any others that meet ALL the specs the factory calls for. There have been independent tests in which Delo's synblend 15w/40 outperformed a few name brand full synthetic 15w/40 diesel offerings, so it's by no means a bad oil.
There are some brands that I stay away from, more due to personal grudge than anything else.
So, Find one that works for you, and stick with it as long as it makes sense.
The filter I have for the between-change duration is Mahle. (Got a couple extra from IDParts last winter)
I had a similar situation with a full new top end going on a well used short block at the end of last year. Full service, new filters and fluids all around, and the first oil change just came up last month. Because it had blacked up so fast, I decided to do a flush change, and bought a case of super cheap cheap ($15/case) oil filters from Rockauto. Drained oil, changed filter to one of the cheap cheap ones, and put 4 quarts of 0w/20 (I think) and 2 quarts of Marvel Mystery Oil. (basically cheap solvent that won't eat seals). I ran it at a fast idle (1100rpm) for about a half hour, no load. until it was up to temp, then drained that out, and changed the filter to the Mahle, and refilled with Mobile1 TDT. (this was a 3000 mi change) I intend to do that the next interval or 2 and see if it helps keep it cleaner over time. (Also sending samples to Blackstone Labs)
I'm not putting this out as a recommendation. In fact I have no clue at this point, if it will help, hurt, or be just a complete waste of money. I strongly suspect the last, but I do want to know.