I think that out of that bunch the .25-06 is the best and then the .243. If you want something that shoots as flat and hits harder you can take up .270 Winchester.
I compared the ballistics at the Remington website and...
A 100 grain core-lokt in .243 a 120 grain in .25-06 and a 130 grain in .270 are almost identical.
The trajectories out to 300 yards are so close that youll never notice the difference in a real world situation. (If you wanna split hairs the .270 wins)
The energy of the bullets is also very close within reasonable distances. The .25-06 and .270 are very close and the .243 falls a little bit behind in this class.
Out to 300 yards the .270 has a edge in velocity but after that the .25-06 takes the cake.
Basically whatever round you choose will have you well armed and the deer and pronghorns wont be able to tell the difference in what hit them.
I love the smell of fresh shotgun in the morning.