A:Answer With a new washer it's usually recommended you get new hook-up hoses. If you look at the Bosch washer description on the website, it should say whether or not it comes with hook-up hoses or whatever else you need for the washer. For a dryer you will need to get the exhaust venting tube - don't re-use the old one since there's probably lots of lint in it anyway, and better to start with a new, clean one.
If the installation kit says it's for washer AND dryer 1 should be enough. Just read the description of what's in the box. I recently bought a new washer and dryer and the site recommended the additional items needed for hooking them up - new hoses for the washer and the hook-up kit for the dryer which was the exhaust hose and misc hardware needed to attach it.