I'm doing a cheat here. If I was commissioning The King with investment/flip in mind, I'd have him draw Captain America vs Red Skull with the American flag and a Na'zi (insert Aldo Raine voice) banner draped in the background.
Of Kirby's creations, O.M.A.C. is my fave so how could I not? Brother Eye would have to be in the background.
If I was going for something with personal meaning, I'd have Kirby pay a homage to his cover to Super Powers #6 (v. 2, 1985). Not a recreation, but a homage to Superman battling Darkseid with Earth in the background. Of course, I'd have to travel back to 1977 and then wait around for 8 years as a man out of time for that to happen.
I don't do commissions often, but I do get to tempted to see how artists will interpret a character that I think is good fit for them, but they have never drawn. In this case, I think He-Man would be a good fit for Jack. But He-Man's design itself, although iconic, is kinda boring, so I'd have Jack draw He-Man riding a Wind Raider to get that Jack Kirby vehicle in there.