To me the resale is of secondary concern. The difference should be immaterial as the greater daily drivability of the 991 GT3 should also make more people consider it for that use than the 997.

If you are mainly going to use it on track get the buckets. If you are going to use it as a daily drive and only occasionally track it get the normal seats. Buckets are a pain for daily use and the standard seats are adequate for occasional track use based on my experience.

You are going to enjoy this car so much! The engine noise at full acceleration is addictive - from the inside and outside of the car.