I have a couple of bikes with SS 635 ERTO wheels and an extra set I want to build up in the States They are great rims but need some type of drum brake to avoid slippage when wet. The Schwalbe Cruiser tires are a great choice. but these are not a setup for long distance touring as there are as many or more aluminum rims here in Asia as there are SS or steel. My suggestion is to get the best Aluminum rims you can and skip the Steel rims.

IMG_20170721_174116889[1] by Bwilli88, on Flickr
This is the Sram version of a 2 speed auto hub with a coaster brake.

IMG_20170721_174128741[1] by Bwilli88, on Flickr