Re: .25 caliber options
The 25-06 is a fine round in and by itself. As stated in a previous post the 257 Weatherby is an awesome cartridge. I have 2 Weatherby rifles in the 257. I also have Mauser action in a 25-06. Both of these rounds really like the upper end of loadings as they were designed to be fast.
The 257's I shoot the 115 Baltips and the 100 grain TSX's. The 25-06 shoots the 87 and 117's.
It all depends what you want to do with the rifle if you have the long action and expect to shoot mainly deer and antelope along with some varmints the straight 25-06 is just fine. And it won't cost you more for bolt work, dies (if you have 25-06 already), brass etc.
BUT, if you are into speed and want more without the bolt work then maybe get the AI version. Just make sure get a reputable smith with some experience with this cartridge.
That 25-06 has plenty of stuff to do what you need it to do out to about 400 and beyond with right bullet, load and practice after about 700 it's out of gas. I have never tried the Berger's.