I would go for an under mount double sink, simply my personal preference for look and most importantly easier to clean/wipe around straight into the sink without bits getting caught... as for chips, we chose a Franke sink that was a "real double" sink big enough to fit a fairly large pot which comes with a drain tray... some "double" sinks are more like one & a half so do your research... also on chips, a lot of it has to do with the bench top and not necessarily the sink, as much as I have a contemporary/modern taste I have gone against all odds and chosen a stone top with pencil edge, simply because the I've seen so many chipped square edge stone tops at family & friends who have built or renovated in recent years, although more popular and in trend, they now wished they went with a pencil edge which doesn't chip as easily... but again personal preference, so go for what you like and what works for you and it will look great and you're bound to love it! Good luck :)

I only specify an overmount sink for clients if the benchtop surface warrants one. The last time I did was because the client wanted a timber benchtop. I managed to find a beautiful black quartz composite sink that worked well and looked like a feature in the kitchen because it matched the colour of the cabinets. My usual go to sink is definitely undermount because of its aesthetic and practical advantages. Small chips can always be smoothed out if need be but really, there is no substitute for being careful!

Early Settler has fireclay ones for around $1000.

Congrats on doing the planning and thinking about how you will use the space, absolutely essential even if you don't do a lot of cooking. A well planned, functional kitchen will make your life easier and add value to your home. I am an avid cook and long time renovator so have done many kitchens in my time. Looking at your space and how I personally use a kitchen I'd suggest two sinks. A small prep sink on the stove side and a large double bowl sink on the island, with dishwasher underneath. I think your hotplates are in the right location as long as you have at least a 500mm or more of bench on the wall oven side and then ideally approx 2m (if you have it) from the hotplates to your prep sink. This divides your kitchen into zones, prep, cook on the back wall and clean up, serve on the front. If you tried to put everything on the back wall it would be too crowded and not work. Think about a desidng that allows for two people at all times to be in the kitchen, you do this by dividing your kitchen into zones. Prep, serve, clean up and think about how you entertain or liaise with the family whilst you are in the space. I hope this helps and best of luck with your new kitchen.