Rebel,
whereabouts are you going in B.C.? Its a beautiful place. Rugged rugged mountains, glacier fed rivers.... Amazing. I would go with a 40mm objective. It allows you to use a medium or short set of rings. The scope will be in a more natural position. Why the 4.5 x 14?I hope it isn't an adjustable objective. AO's are perfect for prairie dogs but not in the mountains. I personally use a Leupold VX III in 2.5- 8 x 36mm. Its plenty of scope for me, but thats a personal thing I suppose. The 300 ultra is a thumper, on both ends; good cartridge though. best of luck!