Given that far more people are interested in suitcase than in Brompton rolling wheels, I went to look what consensus might be reached there and it is skate wheels:

Best Luggage Wheels | Luggage Tips | Top-Travel-Tips.com
Understanding the Types of Luggage Wheels - Lofty Luggage

The issue then remains of weight. The Brompton EZ-Wheels weigh 32g each and 60mm skate wheels offered by Bikegang are listed at 57g. Two wheels will hit me at 50g