I think any of those 12% creme developers should work, I have bought two different brands and they were practically the same, one was in a white bottle branded "Salon Smart" and the other yellow branded "Innovative".
I'm pretty sure this stuff will work for keys as well. When I finally get some of my current projects finished I'm going to clean a whole bunch of Amiga stuff, take photos and videos along the way and write a guide for this magazine/handbook I want to make.