There's not much over the counter oil that is VW508 compliant for warranty. Pretty much the only ones that are available in the US are the dealer stuff which is now Mobil 1 ESP X2 0W-20, the Liqui Moly Top Tec 6200 0W-20 and Castrol Professional LL IV 0W-20. Of those the ESP X2 is available at NAPA I believe, LiquiMoly is available in a bunch of places including Amazon.
However I'd recommend going FCP Euro. They basically give you free lifetime oil changes less the cost of return shipping. Just return the used oil in the old bottles and old filter to them and they'll refund you. Order the new change, change oil and filter, send old oil and filter back. And yes, they actively encourage people to use this and even have a video on how to properly package oil for refund under their lifetime warranty. Their oil change kit includes 4 quarts (add 1 more for 5qts which is basically what our cars take) and a Mahle filter.
VW Oil Change Kit (0W20) - Liqui Moly 04E115561HKT1 (edit looks like they changed to a Hengst filter for now)
I already have one of these kits sitting on my shelf even though I won't need it till 30k miles with the 2 free oil changes.