annmarie2 this one looks like there's about 6 1/2 to 7 feet edge to edge. and no - 6'3" isn't too much. My kitchen has 7 1/2' edge to edge, and provides decent space for 2 people to work.
Samantha Gardner Online you should be able to find your answer on the NKBA website The National Kitchen and Bath Association gives you guidelines for designing your space for both function and practicality, and should include minimum and maximum distance for the best use of the space.