I know many of you have done this and I am taking the cabinets out of my house and going to repurpose them also.
How high off the bench did you mount your uppers? I am thinking going 15 inches. Thanks,
I mounted mine 24", it gave me room to put a small under cabinet fluorescent light, a clock, my sprinkler controls, and my cable remote box on the wall behind the work surface. Under it is the lower kitchen cabinet that I put a new top on- it is basically a craft work area or for things my wife likes to do.
This is not my main work bench tho I wouldn't even consider putting one there, it limits space that is needed to do large work that requires the height.
Above the main bench I put shelves 12' x 24" that are 40" above the bench under the shelves I have 12' of pegboard on the wall for frequently used tools. Works great for me. Good luck