With 2 feet of counter in the way, you won't have the leverage to easily lift and close a big single hung window. Depends on how strong/tall you are and how easily the window slides, both now and after 10 years of use.

That might argue for two smaller windows, despite the mullion.

Or perhaps an outswing, hinged at the top, although if you want an insect screen that won't work so well.

Do look at sliding windows too. Even very small double or single hung windows are very difficult to operating with a counter in front of them.

Even with the walkway, a picture window in the center flanked by two narrow casements may still work and give you the best view. The picture window in center idea also works for sliders (we have this) and awning windows (top hinged and tilts out).

If you have a great view, try to get the tallest window you can.

Bmorepanic - I tired to find a picture of your window but couldn't. Can you send me a link or post the picture and the measurements? Any issues with the track getting dirty?

I tried to find the picture window / casement combo but can't find one in this small of a size. I think the smallest casement I could find is 17". Make all 3 windows 17" each and I thought it may look funny.

Double hung means there are upper and lower sash and both can move.
Single hung, ditto, except the upper sash is immobile.
Two windows side by side is referred to as paired or coupled. The act of pairing (or tripling, etc.) windows by adding a molding (mullion strip) is called mulling; for instance a pair of mulled double hung windows, or a triple mulled casement arrangement, and so on.
Mulled windows fit in a single rough opening in the framing. When another stud or studs separates the windows, they are referred to as grouped.
Manufacturers will mull windows up to a certain size at the factory, but really large units are assembled on site.
Trivia: there are triple hung windows, consisting of upper, middle and lower sash, each operable independently.
Casey

Okay...here I go again trying to be helpful, but really not knowing for sure if I am....I don't know window lingo like sashes, mullions, casements, double-hung, and single hung.

But I like pictures of things, and you asked for pictures and sizes so hope this helps somehow!

Bear in mind that this picture is from my old kitchen. We kept this window as it was relatively new. I find it to have a great view of my backyard. It slides to the left.

It measures 58" wide by 38" long. Please excuse the ugliness and mess. It looks much better since the remodel!

KA:)