Here’s another perspective on scope magnification. Increased magnification can only be had with heavier scopes. Cutting ounces and pounds from your pack is an important consideration, because no matter how good of shape I’m in, I always wish I had more energy at the end of a ay or elk hunting. Most guys I know who kill a lot of elk with a rifle do so with compact, lightweight scopes. I can very consistently make shots out past 400 with an 8 or 10x top end - you do not need a lot of magnification for elk. If you need more magnification to identify an animal, use a spotting scope. Most elk are killed under 200 yards. Are some killed at long range? Absolutely, but I’m my experience, that’s the exception. I know I don’t feel confident enough shooting at a living animal so far out as to need 20x magnification, so it’s just extra weight for me. You don’t need to see their eyelashes to know which animal to shoot at and accurately place a shot. Others are capable of that. If you can’t get within 300 yards of an elk to shoot at, I would encourage you to think about other areas of your hunting skill set to focus on to get to that point. I primarily bowhunt, and we very routinely get inside 100 yards of elk, even in open country. Closing that to 30 yards for a good shot is the hard part, but we still usually end up with elk in the freezer.
With respect to calls, if you’re hunting during normal rifle season, probably all that would be useful is a basic diaphragm call. You could check out Phelps, Primos, or Rocky Mountain. Elk typically aren’t rutting during rifle season (so bugling doesn’t do much), but they mew and chirp to communicate all year. Cow calls are effective to get an animal to stop, and you can call in cows with a call pretty much year round in the right situation. Bulls are hit or miss. Mostly during rifle season though, you’ll be trying to find them in the open first thing in the morning or right before dark as they transition from bedding and feeding areas. No calls necessary.