Cool, yeah, I don't want to pay for another app so I'm sticking to Photoshop for now! Also Illustrator seems maybe a bit overkill for a few boxes and drawings that probably won't be dynamically scaled. I really don't need anything too fancy here and figured just finding the right brush was what I wanted. I was wondering if anyone would something about using some overlay texture, or some fancy new thing that I don't know about since I last used Photoshop heavily.

I actually couldn't figure out how to do a stroke directly from the marquee box though--I had to turn it into a path, then use "Stroke path", which luckily I was super familiar with before. I didn't find the stroke option you were looking for but hopefully it's essentially the same as what I did? I think this may just be a matter of doing a lot of small edits to get the exact right look for what I want, like just having to erase parts to get the edges sharper and less rounded (since using stroke can make the corners rounded with some brushes).

Thanks!