A can of denatured alcohol is useful for cleaning the bed, to ensure good bonding of the print. The kit arrives with all the tools needed to assemble, plus the cable (I think). You may want to pick up a palette knife or similar flat scraper device, but you can find things of this sort locally. It's safer to let the bed completely cool when removing the print and therefore, no tools are needed, but our library people are impatient.

I cannot answer the question about Octoprint, as the owner of the MK3 is in Hawaii, lucky fellow. The black parts are not going to be less strong then the orange, but I expect some people object to the "loud" color of orange and had requested black.