I believe that the 330-06 can do the job you want at substantially lower pressure than the 338 Federal, 60,000 PSI vs 50,000 PSI. That pressure difference is significant, because of increased blast, reduced case life, and the requirement for relatively fast powders. The 338-06 ought to be very similar to the 30-06 when it comes to reloading. I considered puchasing a 338 Federal barrel, but came to the conclusion the 338-06 is an all around better round. Thats where I would put my money.
If you are hoofing long distances in rough terrain in tight cover, the 24" barrel is the way to go. If you plan on hunting an area with more open view, offering shots at over 100 yards, the 26" barrel might be better. I like the way the 26" steadies out the gun and makes it feel more balanced.