I'd think a custom built 357 would be the way to go. Often 357 rifle chambers are less than ideal for accuracy.

I also wouldn't bother with the 357 max or 357 B&D. In my 10" 357 mag contender I was able to push a 200 gr cast bullet 1700 fps, the 357 max would do 1900 and change. In a rifle you should have no problem pushing a 200 gr 1700 fps with the 357 mag.