Joey, We are in a climate crisis that is only going to get worse. So plan for the worst, as you have. Part of that involved your choice of a self-supporting tent (often called ‘free-standing’, tho it is not). Since you’ve made that choice, I won’t bore you with the flaws of T-pole supported tents.
Next come the issues of durability/strength, both over time and in severe weather; price; drypitch; and comfortable space inside. Hilleberg may make Everest ready tents, but the Niak uses their lightest fabric. There are other brands with strong and durable light weight fabric.
Next comes comfortable space. For a basic wedge dome like the 2P Niak, look at the number of sq. feet of the inner floor and the inner height as compared to the same specs for others.
Next comes the price, and the Hillebergs will be substantially more. If you find another brand that meets the other criteria for much less, guess it depends on the size of your bank account and your desire for a Hilleberg.
Ability to pitch without getting the inner wet, or ‘dry pitch,’can make a very big difference, possibly even a life or death difference. Despite glorious weather, it only takes one frightful storm to make the difference. Like some other dry pitch tents, the Niak appears to have a big fiddle factor. Check out the pitching videos on the Niak product page and decide for yourself.
So would also suggest a close look at the Big Sky International tents, like the 2P Evolution. With any of the small companies, obtain a time to delivery estimate in a written email before shelling out for an order. Please consider that small companies are not going to stock large inventories, though.
It may be too early to weigh your decision on polyester; but would suggest being sure that if you go with polyester, look for a minimum of 20 denier, as Dan Durston has done with his X-mids. I have had silpoly’s with less than 20 denier test repeatedly for much lower water resistance, as well as much lower strength.
One last thought; the self-supported tents with one hoop, and short struts to support the hoop as well as the two peaks, are not as stable as those with two hoops that cross overhead, and use one strut to support the peaks; but one or the other design is essential for keeping rain, especially blowing rain, out when getting in or out. My own modified wedge dome, also uses a couple of carbon struts to stabilize the hoops between the peaks and the ground.