Obviously there are a variety of ways of getting there. Now you have a few ways to calculate/estimate your preferred gearing, and make your decision. I put a smaller sprocket on the front because I ride off road and love to have rpm at low speed. So I can't tell you what might fit (bigger) up front. But you don't have to even change the front sprocket since there are many rear sprocket choices:
https://www.jtsprockets.com/catalogue/sprocket/JTR210/
In fact, these are the sprockets they are making today. There is lots of old stock apparently, like the JTR210-51 I got for my X, still available.
Just google JTR210-XX (where XX is number of teeth you want). These sprockets are low cost, and they are durable sprockets.