We tried reversible bumpers last year and really liked them.
For bumper numbers we got 4" white numbers from
https://www.numbers4sports.com/ and ironed them on the Cordura. They looked really sharp. We were concerned that the Cordura would melt, but we didn't need super high heat to get really good adhesion.
Numbers4Sports gives you a price break when you order 10 of each number so it was also affordable. We needed 8 sets of numbers for the bumpers anyway and then screwed up ironing one set on (upside down, oops) so it worked out well that we ordered 10 sets.