Interesting that Hyundai recommends 3 different oil weights. I would review the owners manual again. Those different weights are probably recommended for different climates and driving conditions. As for brand, I am one of those people who believe that branding does not make much of a difference. The most important thing is to make sure that your choice of oil meets your OEM spec.
Why do you think that the 30 weight is better than 20 weight?
5W-20 goes into the fleet vehicles at work, Ford V8 engines, and we drive those around the clock, every day, under severe conditions. I offer you no chemistry charts. Nor provide any science. Just eye witness account that 5W-20 oil works fine in the conditions which I observed. Quite different than a Hyundai Kia cruising at highway speed.
Same way you can watch an online video of how "brand X" was used for a year in a Las Vegas taxi company - it means nothing to you. Same way it means nothing when someone refrigerates motor oil, to see how it pours when refrigerated. It's not a 12 year old Hyundai going across the country on the route you are planning.
Keep that in mind, as everyone offers an opinion. None of what anyone tells you is science. Anything they might refer to or quote is not their research - just something they found online. The only real science, in relation to you & your vehicle, would be if they had a control group of 2007 Kia Sedona w/ the same engine and in the same condition. Then they use the 3 oil weights, from different brands, and drive those on the same course across the country, repeatedly. This experiment is not likely to happen, so you will not have access to factual research data relevant to your planned outing.