Best wishes on your 8K! We don't see that distance very much. I signed up for one last year, traveled two hours to it, just to be told it had just been cancelled due to stormy weather! A group of us that stayed at the hotel got up the next morning and ran the 5 miles anyway.
My favorite distance is the 13.1 miles, or half marathon.
Finished: Walt Disney World Marathon, January 13, 2013.
Finished: Disney Princess Half, February 2013
Finished: Orange Blossom Half and 5K, March 3, 2013
Finished: Divas Half, N Myrtle Beach, April 2013