Which metal wheels for Athearn dummies?

I would like to purchase NorthWest Short Line metal wheels for 2 Athearn dummies, an SD40-2 and a U30B. Unfortunately, I am overwhelmed by the information on the NWSL website, and I don’t know what to order. I would appreciate any help. Thanks.

Call them.

I’m not sure about NWSL, but I have had good luck using Jay Bee wheels, they are chemically darkened. And are a perfect fit. 40" 1/2 axle wheel p/n 102