I bought a pickled oak kitchen from Green Demolitions and since it was 23 years old, it needed some refinishing. My carpenter re-faced some of the cabinets, so I REALLY had to sand and re-stain the cabs in order for them to live up to the nice looking cab boxes he made me. Luckily, my carpenter/contractor fellow knew that pickled cabs are stained with an oil based stain. He brought me a naked piece of furniture-grade red oak and sent me to Sherwin Williams with one of my cabinets with their original finish and the naked red oak. They carry a whitewash stain. The guys there added colors to their product until they were able to reproduce the color of my cabinet door. The stain looks great on the cab boxes, but on the doors and drawers, where I found that I have to make it thicker (wipe on a heavier coat and do not wipe it off). Here, it looks too white.

Are your maple cabs new and unfinished? If yes, there is little prep. If no, you need to sand them. I sanded to rough up the surface, not to remove the finish entirely. That was a semi-satisfactory result. It worked best to sand more and get most of the finish off. Figure out how much you are going to sand so that you will have a representative door to take to Sherwin Williams. So, take the maple cab door that is all ready for staining and one of your white pickled doors to Sherwin Williams and ask if they can custom color their pickled stain to get the maple door to look like the pickled one. You will need to put a few finish coats on, too, using polyurethane or what ever finish most matches your whitewashed cabs. If you can't exactly match your whitewash, think about getting the closest you can and also refinishing the pickled cabs at the same time you do the maple.