I would say go with the 30.06, i know its boring and plain-jane, but it works well out to 350 yards, and recoil is pleasant. 300 win mag is fine, and better for longer shots than 350 yards, but inside that range, bullets work better at 06 velocities (that should get some comments!). Drop isnt much different until you get way out there. A 30 caliber is a good choice, but a 33 or 35 caliber is better, but not absolutly necessary. I just sold my 300 win mag and kept the 30.06, and bought a 35 whelen. Both rifles are used for elk. I dont shoot past 300 yards at elk anyway, only at targets. Shooting 500 yards at targets really humbled me in my shooting abilities though. I know a lot of people that shoot a LOT less than me and they talk about it all the time. Like my buddy with the 30-378 that couldnt hit the 18" gong at 500 yards, and i sat next to him with my "slow" 300 win and rang the thing over and over.
Oh, and you asked about recoil, I'm a small guy, 165lb, and the 300 win never bothered to shoot unless it was lots of shots off the bench. Get out and shoot your rifles from field positions, and the recoil is a lot easier to take. Probably the best elk rifle for the 350 yard shots and under (assuming you practice at these ranges) is the 338 win mag. Which, by the way, is pretty close to the 30.06 in trajectory. Recoil will definatly be more, however. 338 win mag may be the best all around elk specific rifle.
