I think a comfortable distance between the island and the counter is around 42". It seems that you have only 30" between your cook top and the counter. I might be a little too tight. The wall between the entrance and the kitchen could be 4' long instead of 6', you would then be able to move the island a foot which would give you more room between the cook top and the island. Could you switch the location of the toilet and vanity in your dad's bathroom so your enter facing a vanity instead of a toilet which is a lot nicer.

How do you decorate your place, what kind of style, colors, and feelings? That will greatly influence the type of door you might want. Also, think of your budget, and whether you want to install it yourself or hire a professional (you don't need to tell us, just keep that in mind). Then look around Houzz, in the products page, they have lots of interior sliding doors and hinged ones, from elegant frosted glass in a dark wood frame, to rustic reclaimed wood planks. You may not want to purchase that exact model, but it might give you a better idea of what would fulfill your airflow needs without sacrificing style.

x2 what Dytecture said, this is not enough to go on. Most important thing before you do anything, is you need to know lot restrictions in that area and what are the zoning requirements, i.e. side, rear,front, set-backs. In addition the size of your house will also depend on the total percentage of a lot that can be covered by impervious surfaces (structures, decks, and surfaces likes asphalt or concrete driveways etc, which reduce natural infiltration, etc and after you obtain that information, only then you can contact a local Architect and you can roughly come up with the size of your house and layout on the lot... until that, the information you get here it will be useless to you in your case and a waste of time for everyone else. With that said, 40x104 is not a confirming lot for most of the area around here and you will need variances because confirming lot sizes usually start at 50x100, unless you in a section where ordinances permit residential cluster development. Good luck.

Sir you can use Wooden textured ACP as it will be cost effective solution to cover Soil pipes and provide a modern look to facade .