That’s a risk. I already got an answer from tektro : they asked me more info about my need, because they did not understand why I wanted only a right caliper. I’m surprised they don’t know the strida !! 
So maybe a positive answer to anticipate. I’m waiting for their price.
At the moment, I did not find a company that has the caliper alone in stock. Maybe tektro will have some.
You found a nice tektro site in France. Thanks, I just sent them a french email 