It depends on how much work you want to put into it, how much money you want to spend and how particular you are about the quality of parts you want. You can buy a complete kit or buy all the pieces individually. Most kits are cheaper than buying everything individually. However, some folks think the pieces in the kits are of lower quality, since they may be imported from who knows where. Here are two recent posts on this subject:

Post 1

Post 2