Is that series an on-going story? I’ve read Sanderson’s stand-alones (Warbreaker, Emperor’s Soul) and enjoyed them. Usually prefer to start a series if it’s all out/ the end is in sight.
Discussion
The books are so long you might as well start now. For reference the audiobooks are something like 40-50 hours each if I recall correctly. It’ll take a while to get through them.
Stormlight Archieve is his biggest series. He's going for 10 books, like 1000+ pages each, and broken into two main parts of 5 books each. It's epic as fuck, but you need to be ready for it.
And then because Sanderson is swinging for the grand slam rather than just a home run in terms of epicness, even that series loosely ties into his other series. For example 2-3 characters from Warbreaker eventually show up in Stormlight Archive, he has one character that shows up in almost all of his his Cosmere novels, and the overaching metaphysical plot involving the god-like shards affects all of his Cosmere worlds including Stormlight.
If I recommend his work, I usually recommend the Mistborn Trilogy first. If they like that, then onward to Stormlight Archive. If someone already likes Warbreaker that's a good start too. Warbreaker was one of his weaker ones imo.
Those stand-alones you mentioned aren’t really stand-alones. They are important to the larger story (especially Warbreaker at this point at least). Any more info would be spoilers. My suggestion on the cosmere novels is start with Elantris (weakest Sanderson book in my opinion but still really good) and go in publication order so you can pick up one the little cameos and Easter eggs in the books. The rate that Sanderson releases books is insanely fast ( especially compared to GRRM) so you should have plenty to keep you occupied.