I have to agree with the choices listed so far, all will work just fine.
Scopes, in my opinion, should be based more off of what the rifle is going to be used for rather than the caliber it's chambered for. Lighting, weight, expected shot distance, etc. are all big factors as you're well aware of. With the magnums I also require them to be something of good mechanical quality. I've seen the economy Trashco's and Bushnells get the guts rattled out of them and break on a 300 Win Mag.
One brand you didn't mention was Sightron. I'd give them a look too if they're in the price range you can work within.
For me, I'd pick the following:
#1 Choice: Leupold VX II 4.5-14? X 40
#2 Choice: Weaver Grand Slam 4.5-14X
#3 Choice: Sightron SII Series
#4 Choice: Leupold VX I OR Bushnell 3200 or 4200
That would be my ranking.