Ken, congrats on the Civic. My wife had a 2000 EX that never gave us a day of trouble.
Can I ask why you are looking at such fancy tires? The car itself is not at all tuned for performance. If I remember correctly, we replaced the tires on ours with the lowest price of "off brand" I could find. Honestly, I couldn't tell the difference in the way it drove.
Tried the same thing on the Accord EX we owned, and I hated the tires. Goes to show you......
Anyhow, as long as the final diameter stays the same, you'll be fine.
Here is an explanation of tire sizing.
