It mostly comes down to personal taste. I'm a huge cold-war fan, and studied WWII a lot, but I don't care to fly WWII aircraft nor Korean War vintage aircraft.
As for your choices. I have both maps and like them. I just got Nevada map during the current sale. The only problem I'm having is judging my high above the ground from my visual VR view in the Nevada Map. (It could be just natural over desert)
When I was in the U.S. military, my unit had mostly UH-1s and OH-6s. I was not a pilot, but I could go and ride along almost anytime I wanted. I did get to fly an OH-6 for over an hour. (Now, that would be a module MH-6 I would love). Our sister unit had CH-54s. I've spent 11 hour days in one of those, and would like that module also. (Neat Crane fact, there is a limited rear-seat flight control --downstairs--- that overlooks the loading host for sling loads)
Anyway, the first model I chose when I got DCS was the UH-1. For this sale, I chose the Gazelle and F-5e during this sale. Gazelle because it's the closet I'm going to get to a Little Bird. I chose the F-5 because of its relations to the T-38 and because it was widely exported when I served.
Speaking of, if the former Belsimtek coders get freed up I still want that F-4 (and RF-4) for that matter.