Either of the bullets in the calibers you mentioned will work. Black bears aren't all that hard to kill, but you do want something that will penetrate through and through while still giving good expansion. Nosler Partions are a great choice and I will be using them on my bear hunt next week. I hope you have a great hunt.
I'm hunting Saskatchewan black bear May '08 - use your BOW
Everyone I've talked to says that black bear (over bait) is a definite bow hunt. Provided, of course, that one is proficient with a bow (min. 160 lb. draw / 125 grain non-mechanical broadhead).
From what I've researched, many good options on rifle for black bears - 30-06, 7 mm magnum, 300 mag or 300 WSM plenty powerful - should be at least a 180 grain - nosler partition a good choice. I like the Accubond round personally - took down a 1,200 lb. moose in 2004 with one well-placed shot.
Out here in Colorado, and in the units that I haunt, it is a tricky game to figure out how far to pack in on a rifle hunt. You want to get away from the masses that have moved game away from the roads but might want to stay close enough that you are taking advantage of the animals forced movements. There is no universal distance but I like the 1.5 to 4 mile range for day hunts where I am not planning on bivying out. This keeps you in that productive buffer zone where the animals are really...