After some expert advise from @monsterjavaguns, I finally got to the point that I could do a trial run on a project. Not quite where I want it, but it's a good rough draft.
@monsterjavaguns yeah I was relatively pleased. I'm quickly leaning that a lot of GIMP time on the photo can drastically change the outcome. All and all I think I'll be able to make it work well.
@thaj Absolutely! You could also tweak your relief a bit by sculpting on the displaced results. Definitely let me know if you think you could use any help with anything.
@monsterjavaguns Hahahaha I'll have to get good at this and then attempt the sculpting stuff. That's scary for me 😱
@thaj Not bad for a first start!