If you anticipate elk hunting later, the .300 Win mag is sufficient — but just. It will kill elk, but please don't go smaller.
Having been on a few western elk hunts I can tell you most guides would say the Sendero is a bit heavy for carrying up & down mountains all day. I carried a Weatherby Accumark on my last elk hunt and felt the weight as I climbed 12,388 feet the first day. (GPS data.) There are hunts on ranch land that are more fitting for a heavy rifle, but there is a reason hunters like "mountain rifles" to be light.
The limiting factor on most elk hunts is the hunter's ability to keep climbing up and down mountains for a week straight. If you are ABSOLUTELY CERTAIN the added weight won't hinder you, you can go heavy. If not, every guide I've talked with recommends the lightest gun the person can shoot well.
That said, I like a heavier rifle when it comes to shooting. Even when winded from a hard climb I can shoot a heavy rifle. A can't say the same for some lighter guns. My primary mountain rifle is a Model 70 SS in .300 Weatherby — it's not an ultra-lightweight, but it's not a heavy gun either.
For general long-range practice, either the Sendero or a Savage will do. I would opt for the Savage mostly for the trigger, but both are good guns that are easily upgraded later if you so choose.
are GREAT for long-range target practice but they suck when you need to wear ear-plugs all day long on a hunt where you could trip over elk or see one at 650 yards. For that reason I hunt without a muzzle brake
on everything but my .338-.378 Weatherby magnum. Savage offers a twist closed muzzle-brake that you can use closed (no brake) unless you have time to set up and put earplugs in. That is what I would recommend. Buy the Savage with a twist-open brake & you will have a gun that fits everything you anticipate doing.