I would definitely put the appliance pulls on the DW and fridge drawers. Unlike your cabinet drawers which are on slides and so easy to move, the DW and fridge drawers almost have a suction action to them which require a "tug" to open. I have never checked this but I wouldn't be surprised if the screws on the appliance handles are actually bolts and so are heavtier than the drawer pulls and are built for the heavier pull action required. Using the 12" ones would give a uniformity to your appliances. I have a bank of 15" drawers, a bank of 19" drawers and 2 banks of 30" drawers which are shaker style. I have the same not quite 7" pulls on all of them with only one on the 30" drawers. They are all centered in the middle of the drawer. I know that some people center them on the top narrower drawer (cutlery) and then raise them to be set higher on the wider bottom two drawers. That drives my sense of symmetry up the wall. P.S. what do you mean centering them vertically?

I will second what pussuskattus suggested...although it is definitely more work/time, we found that it was very worthwhile to mock up the drawers and try out our handles that way. We ordered various sample sizes of our handles and DH cut some scrap wood planks in the lengths of our drawers. We then just placed the handles on each board and it was VERY quick and easy to determine which size to go with. It was surprising what we found...definitely some different outcomes than what we had thought before mocking up. There would be no need to cut wood, though...could easily just use posterboard or scrap cardboard from a shipping box. And the ribbon idea would be easy, too. Would save the step of buying the pulls if you don't know for sure yet what you want. Good idea for next time! Good luck with your search on the vintage pulls!

Some people are afraid that if they put two pulls on a drawer that means they cannot open it with one hand...not true! As long as you have decent drawer hardware, you can use one or two hands w/o hurting the hardware or the alignment. I use one hand probably 90% of the time to open my drawers...and no problems yet! Here's a kitchen w/two pulls on drawers >= 30" and 1 pull on drawers The cabinets are, left-to-right, 33" drawer base, 18" trash pullout, 36" sink base, 24" DW, 27" drawer base, 31.5" oven cabinet. In this pic, the cabinets are: 24" drawer base (around the corner), 30" warming drawer + drawers, 6" pullout, 36" cooktop cabinet, 6" pullout, 31.5" MW Drawer + drawer.

I did the 160mm size for the drawers which were over 30" and the 128mm size for everything else except for my narrow pullouts. I used the 3" pulls for those. I liked the 96mm on my narrow drawers (15"), but DH preferred the 128, so that's what I did. I think if you stick with the 128 everywhere except for the one big drawer you won't even notice that it is a different size pull.