Looking for my first diesel truck! Needing some information and advice.

Right now my top 3 options are the 2nd gen 5.9 24v cummins, 7.3 IDI, and the good ol' 7.3 Powerstroke. I know all 3 of these engines are supposed to be very reliable especially when maintenance is done regularly. I'm mostly looking for things I need to be worried about and roughly how much normal maintenance costs per month. Here's what I know already:

2nd Gen Cummins: I know I'm probably going manual since the automatic trans are awful (unless I find one with a built / new transmission with paperwork).

7.3 IDI: Slow asf, reliable asf, no computer, overall easier to diagnose problems, should be cheapest to maintain.

7.3 Powerstroke: Not as slow as the idi / basically just a little better idi.

I'm looking to get a diesel to haul some stuff, roll coal, last a bunch of miles, and overall just wanting a cool truck. I know some people are gonna say "Just get a normal truck" but I want one that will last a while. My current budget for a truck is around $7,000-$7,500 with around $1,500-$2,000 for maintenance. I have seen some good trucks around me with around 200-205k miles for around $6,500-$7,000 thus my budget.

Other diesels like the 6.0 and 6.4 are not off the table but if I get those I will baby the heck out of them until I can sell it or trade it. I'm familiar that both of these engines should be bulletproofed and despite what everyone says the 6.4 my brother has is a very good truck with no issues.