Well the design is looking great, I'd say you are just about ready to start building. Thought on upper slide doors I have the same type of layout the doors are framed and panel, the panel is a cane material like they use on chairs, gives a nice contrast.
I had a Cookmate 4200 2 burner flush mount in my old boat loved it. That looks to be a good price from the site you linked. It will also maximize the storage under neither.
Counter material: Formica is very inexpensive and easy to make up or you can get pre-made at HD or Lowes.
I agree with Redfin on the issue with block ice. how about a small transfer pump with a float that would go to your sink tankage. just a thought.
Guess its time to get busy spring is on its way!!!!