A good tile installer that knows what he is doing, can easily remove that single piece of tile.... carefully replace it with another one. Do you have another extra pieces of the same tile? Do you know what brand and color the existing grout is? That will be more of the issue trying to get the grout match to match up or the finding the same tile (in the same dye lot) if you need to buy another tile. Did the heat cause the break or did a pan bang into the glass? Consider installing a heat resistant Lumicor or 3 Form panel behind the stove. Any flat material that can be sandwiched between two resin panels. 1). Crushed glass. 2). Fabric. 3). Fabric. 4). Fabric.

Yes they do have similar styles in porcelain, but to me it doesn't look the same. Search around that site and see if any of the other tile designs in other materials strike your fancy. I know you said you don't like the subway, but you could get a glass tile in a 2X8 and lay it in a herringbone or find shorter ones and do a chevron. Don't know if you care for mosaics, or penny rounds, those would also look nice. You are going to have to narrow it down to a look you are drawn to, and then go from there. Search kitchen backsplashes on here to get some ideas as well.

If you love the marble tile, go for it! You can always buy a stainless or white range hood backsplash like this http://www.wayfair.com/Air-King-Range-Hood-Back-Splash-SP2430-AXK1174.html to slip in place when you are cooking something really messy. I have a travertine backsplash and use a stainless sheet when frying. It works great and no worries about stains ruining the stone.

the sink should be at 33" from the floor. your countertop height will depend on if you're using a top mounted or insert sink