Troparctic availibility

North Jersey
I've been using Motorcraft 5W-20 in my mom's 2001 Escape. Now that Walmart does not carry this oil, I am wondering where I can get TropArctic 5W-20 synthetic blend, which I've heard is excellent. Walmarts in North Jersey don't carry any TropArctic, and Dollar Tree only carries 10W-30 and (uhhh...) 10W-40. I can't figure out why they won't order 5W-20 or doesn't cost any more. Who buys 10W-40; no car has called for that stuff in over 20 years.