I think either option would be fine. Two big pendants is very in right now and yes, I think at 16'' by 13'' they would be big enough. I will add though that 16'' is tall and if you onl;y have 8 feet ceilings make sure you are okay with how that will look. I *loved, loved* a pendant that was 18'' long and it was just TOO BIG for my 8' ceilings. If you like the look of two big lights, go for it. Does the rest of your kitchen look really symmetrical? If so, then maybe you do two to keep that vibe OR maybe your do three to shake it up a bit and keep it from getting visual stale and predictable. Hang balloons, paper plates or cardboard cutouts to get a sense of how each would look - although, if you are like me, you had to make the decision before the island was even there, during the electricial rough-in stage. HTH but not sure it did b/c I didn't give you a definitive answer. Sorry.

"Question: will support post on each end of the 10ft overhang be enough or do i need another post in center??" No and no. You can't do it like that. You could have your fabricator cut slots into the bottom of the stone and fill the slots with stainless steel or composite rods set in a bed of epoxy or acrylic adhesive designed for rodding. 30" long at a minimum and spaced every 16" or so. Alternatively, you could run a 2" steel square tube between the three posts and set the stone on that. Painted flat black and set in 3" or so, it will be somewha inconspicuous. Check your door swings first, please.

Darlene, really? did you actually search, "20" pendant lights? " I found many, many sites. here are five https://www.hayneedle.com/lighting/pendant-lights_size-large-over-20-inches-wide_list_187872_33977 https://www.wayfair.com/filters/keyword.php?keyword=20+inch+pendant+light&filters=at_6087_144792~465762 https://www.lampsplus.com/products/pendant-lighting/size_medium@@@@@-23-@-30-in@@@-wide/ https://www.1800lighting.com/ceiling-lighting-pendant-lights-large-pendant/ https://www.houzz.com/products/query/large-pendant-lights

We are building the home right now and we need to decide on the wiring for our design appointment. Let me see if I can find a picture from model