There is a dude on another forum that loves to post about the virtues of the 7-08. And he has several pics of elk and deer dropped out to considerable ranges (500+ yards). Anyway, of the two you listed, I would definitely go with the 7-08.
I don't think a 25-06 would be well suited for a 20" barrel. Maybe a 22", but I think 24" is appropriate. The 25-06 is however an excellent cartridge.
The downside of a 20" barrel is going to be noise. Especially if you have a young hunter who might forget hearing protection, the noise will cause more permanent damage then one with a longer barrel.
I'm that dude.
So far, three bulls with three shots. Farthest was 346 yards, biggest was 225 yards.
One antelope, one shot.
Buncha deer, one shot each. Farthest was 541 yards.
140 Partitions, except for the biggest bull, that was a 140 AB. 2873 fps for the Partitions, 2850 fps for the AB.
P
