So not having the ac yet.... And bear with me here..... I'm thinking out loud, so...... Being inside the shop that sits at about 76 all the time, I think the 24k will be enough AC that office is the coolest room in the shop.... The Mini Split will be for supplemental cooling just for the room...
You will get heat build up in the shop. I would run the window AC but build it into a closet like room where you can capture that heat and blow it directly out side from that room.
If you were smart you would run 2 window AC units. The second would only run when it is the hottest out and the first would not keep up. Just get a temp controlled outlet that kicks on the second AC when a temp above what the first AC is set to is reached.
Kind of like a 2 stage furnace. So say a 24k main AC and a 10k secondary AC. This way you are not running more AC than you need. It is more efficient to run the AC for a longer run than to have it keep shutting down and having to pump the compressor back up.
Just a thought but if you have the room it is what I would do. Mini splits cost much more than window units.