I need to see the kitchen since the size of pedants is really decided on the style of the fixture. BTW I only like pendants that light the island not the ceiling and because these are in view of each other they also need to compliment eachother So post pics of the space the table for sure.

There are some good rules of thumb for this that you can google - I also suggest blowing up balloons to approx the size pendant you are interested in and hanging them from ribbon at the correct length, then live with that for a few days to see if the scale is right, whether it blocks anything in your line of sight, etc..