The 7200 is a faster drive. It should work, assuming it meets the drive-type specifications for your computer.
Bare means it does not come with the encasement kit (connectors/wiring). If you are replacing an existing drive, that drive already has the encasement kit holding it in. If this is an additional drive, you will need to purchase an encasing kit, if you do not have one.
IIRC, I recommended you do a search on Youtube. Youtube has many installion videos. They give some good info and demonstrations.
can one get a new hard drive with the OS already installed??