You are just replacing the doors, not the cabinet boxes, correct?

If you decide to replace the cabinets -or- you can move your cabinets around, I strongly recommend moving the DW & Sink to the left and putting the drawer stack b/w the sink and corner - that would give you a really nice stretch of counter for your Prep Zone! Right now, you have very little workspace where it's needed the most - b/w your water source (the sink) and the range.

You have an island? I don't see it in the pictures. And, you want to add a peninsula? You do not appear to have room for an island in your Kitchen, especially if you add a peninsula.

What will the purpose of the peninsula be? Just to add seating? Unless you're moving other items, it won't add anything for the primary work zones (Prep, Cooking, Cleanup) b/c they will all be in one small corner - the corner b/w the sink and range.

Regarding colors...

How "white" are your cabinets? Pure white? Off white? Other? (It's hard to tell on a computer monitor as computer monitors usually do not show true colors.)

I would be careful that you don't get a counter or backsplash that makes the cabinets look "dirty" or brings out undertones of yellow or blue - unless that's what you're going for. There's a thread right now from someone who thinks her cabinets look yellow b/c of her backsplash and counter.

Can you hold off selecting a counter for now? If so, then I suggest you wait until you have your new doors in and you've re-painted your boxes (assuming you're keep them). I would also paint the walls and refinish the floors. Once you've done all that, I would then bring home some large samples of both your backsplash and counter choices to compare - materials can look different depending on several things such as the angle (horizontal for counter, vertical for backsplash), wall color, cabinet color, flooring, and even lighting - both daylight and artificial light.

(If you're keeping your cabinet boxes, you may have to paint them to match the doors - I doubt you'll get a perfect match to your current boxes.)

Personally, I've always liked darker counters with white cabinets, but that's my preference, not yours.

BTW...your link did not work, here's a link for the Winstead door that I hope works: http://www.aristokraft.com/products/winstead?prod={B24B42C8-3349-440B-9685-F0190C182820}

If you go with Oil Rubbed Bronze, be sure it's a finish that won't wear off - look for a "PVD" finish.

Regardless of what finish your fixtures are, I recommend going with either chrome or brushed stainless steel for the drain. Most cleaning products will damage nickel and other materials.

You could put in a farmhouse sink if you hack the sink base - but I think you would be better off getting a new sink base that's designed for a farmhouse sink if that's the sink you want.

For a sink, I would stick with brushed stainless steel or Silgranit (mix of stone and acrylic). Some people like porcelain or fireclay, those are possible options as well - but look at the pros & cons of each b/f you choose.

The materials are my recommendations - others may recommend different ones.

Based on the things you want to do - adding new cabinets for a peninsula and island (?), new doors, and different type of sink, I think you might be better off replacing all the cabinets.

Yes, The Kohler Whitehaven "short apron" style farmhouse sink can be installed on a standard sink base. I have one (picture in my "my pics" idea book) and I love it. It is cast iron, comes in different colors, and there is a two bowl - uneven divide - or one bowl option. The Kohler Vault which is a stainless apron front sink also comes in a "short apron" style.

I think LG Minuet is the quartz that is closest to marble. It is very authentic looking and the scale is not overwhelming. I've seen it installed and it's stunning.