Looks like you have several things to consider in the layout. What the view out the window ? Do you really want to see more of whats outside? Cooking is always best on the outside wall to get it vented, island cooking is a last resort, downdraft dont work well at all and the island hood is typically obstructive. Looks like the wall should come out to open the space up. Best advice is to have a designer come to your home and see it in person. There are costs associated with every change and it is very difficult to judge just from photos.The design phase is the most important part of any kitchen remodel the builder is only going to install it as the plans layout. Find a great designer that makes house calls :)

There are many examples on houzz of contrasting counters for perimeter and island. For example butcher block on island and stone on perimeter or a solid color on one and something with movement on another. I would only mix two stones if one had movement and one was fairly solid. The stainless on perimeter and something else on island sounds good to me. Here is a pic of stainless counters with what looks like a stone breakfast bar. (I hope I understood your question right). http://houzz.com/photos/3137660

I would suggest you take out the cabinet that is to the right of the stove and use it elsewhere in the house -- perhaps in the bathroom or dining room with a hutch above it. Then, I would suggest you have someone install a lazy susan cabinet in the corner between the sink counter and the stove, meaning you would move the stove down a bit and have a small cabinet/counter top to the right of the stove. I would suggest you have the cabinets refinished in white and then paint the walls a pastel you like. If you would prefer white walls, then add white-painted crown molding and paint the ceiling a light neutral blue, such as Sherwin Williams Niagara Falls Blue. Then, I would suggest you choose a favorite accent color and use this sparingly in accessories like towels, pot holders, small vases or floral arrangements, and a valence above the triple windows. For a genuine 1940s look, you might have white ceramic square tiles with a rectangular red border installed as a back splash behind and above the stove. If you are replacing counter tops, I would suggest a light color such as white with a beige or light grey vein or striation for some sort of pattern. You might be able to find the same color and design in floor tile OR opt for a wood floor as another poster suggested.

You have a good nice project planned here, with your kitchen now a part of large living space. Here, though, are some cautions and suggestions. Your extra-large peninisula counter and full window wall over the sink seem to be features that you like and want - but they also cause some problems with this plan. If two people are ever in the kitchen, one will be trapped there. And even for one, the peninsula forces an irritating hike around it to the table for serving and clean-up. Table and array of counter stools are uncomfortably close together, creating congestion especially when occupied. And while your back wall may well contain a fridge, wall ovens, pantry and cook-top, it would just barely do so - and leave no other space at all for counter. This, together with your nice bank of windows on the outside wall leave no space at all for upper cabinet dish storage. I agree with Laurie that an island here would be much preferable. I would put the sink and dishwasher on an island, with fewer stools, and some mid-height dish storage - letting gatherings of more than two or three enjoy the table in a conversational arrangement instead of facing away from the room in a row. I would also minimize the window array a bit, and extend the kitchen toward the dining table window a foot or so - and put the wall ovens at this end of the "L" - with no side wall at the left. This would distribute your countertop space more happily among your work stations, allow for some upper cabinet storage, and make the kitchen feel more part of the nice big room, instead of separated from it by the peninsula. Perhaps a careful in-person visit with a kitchen designer would be wise before you build this fun new addition. Good luck! Mark