The most important thing to remember when searching for a cabinet pull by size is that the primary size given on the website is NOT the total size of the pull, but is the distance between the holes, known as the drill centers. This is especially imporant to keep in mind when looking for a pull to fit a pre-drilled cabinet. This is true even for wire pulls, where the end of the pull does not stick out any farther than necessary beyond the screws, and is even more relevant for bar pulls where the edge of the pull can stick out an inch or more beyond the screws.
At CabinetHardware.org, we offer hundreds of different four inch pulls to suit your needs. You can use the pictures at the top of the page to navigate to your ideal style, and once you find your style you can drill down through the available finishes as well.