I'd definitely go with Schwalbe. I've got a Burley Nomad too, but it's way down in the crawlspace under my house and I don't feel like checking the tire size -- but you mean ISO 305, right? You could definitely get a pair of these:
https://store.bicycle-evolution.com/schwalbe-16x1-5-marathon-racer-bike-tire-40-305.html .
Personally, I don't see the point in putting a narrower tire on the Nomad, especially if you're going to carry significant weight. 47-305 would give you a wider range of choices from Schwalbe.