Since you threw out money is not an issue folks put up some expensive elk hunts.
I would look inti a ranch or OTC hunt in Colorado .
You looking to just shoot an elk or actually have a great hunt for one ? That can be the difference in your choice.
Personally I would find a nice backcountry type hunt, maybe horses involved, or a large ranch in either Colorado or NM.
You might be pushing it to find a hunt for 2021 now though, many outfitters will be booked for next year.
Good luck and great on you for lining one up for your son.
You live in Wyoming why didn't you recommend anything there? Some of the best elk hunting in the nation is in Wyoming.
License application is in January plenty of time.
He asked for guaranteed draw, Wyoming does not have that.
I do know some great elk hunts to be had with a General tag, 3 PP to draw last year.
Wyoming does allot 25% of licenses to a random draw that he could have a chance in, odds are pretty long.
For an ultimate hunt with the PP I would tell someone to look into NW Wyoming. Not for me though. Pack in, possibly migration late with hundreds of bulls, big country, grizzly bears and wolves.
For his needs sounds like NM or Colorado is the ticket. I just don't think it would have to be a $10,000 elk hunt to be quite the experience. I would look for a wilderness experience, but you want good odds on harvest too.
Trans Pecos actually sounds like just the hunt. Texas native, free range elk. Probably on a very historic , large ranch and no other pressure.
A ranch hunt anywhere, well almost, should have very limited pressure and good harvest odds. A wilderness hunt would be a very different type of hunt and success rates certainly wouldn't be as predictable as a ranch hunt.