I agree with others- as many sockets as you can fit and drawers in every cupboard
We had the space, but went for a peninsular instead. The room looks more spacious and its still as useful as an island. Another option my in laws have, is an island on wheels. https://www.johnlewis.com/eddingtons-leverton-beech-wood-kitchen-butchers-trolley-85-5cm-natural/p3126058?srsltid=AfmBOoqV-f_-15Fu8lkAUf1Y4CXDvpZzCKrGPKYE63yAokCEXI3GDqFFiB0
We have cupboards up to the ceiling- no dust to clean off the top and more storage. I keep things up the top which I don't use often and have a fold away step ladder when I need it.
Check the size of the plug hole in the sink. We have a butler sink, but it never occurred to me that the plug hole comes in different sizes- and ours is woefully small, only 4cm across. We can't use the basket to catch food debris because its clogs within seconds and is a PITA. Get a plug hole at least twice this size for your own sanity!
If space is a premium, you can get a drawer which goes within the plinth. You do need absolutely flat flooring though.
We have lighting on different circuits- so we can have one over the cooker, sink, all on, some on etc. Also, ensure they are positioned well. In a previous property, there was 1 light in the centre of the room, so whenever I was washing in the sink- it was in my shadow. Now we have a downlight positioned above the sink- so I can see my woefully small sink hole!
I read a similar thread before we did our kitchen and someone mentioned having an 'appliance garage'. I love the idea of a kitchen or utility so large, you have a dedicated area for ALL those plug in appliances- blenders, mixers, choppers etc 😆