If your buying a PPC Mac there's a good chance your going to have to fix it / clean it out with them being so old. AND with Apple being the way they are you will most likely need some special tools for dem silly screws SO here's some options I found that are pretty cheap and get the job done.
Silverhill 20 Piece Tool Kit for Apple Products 14$
For things like Mac Mini's you might need a thing object to lift up the case, you can buy things that do the job from ifixit BUT it's a lot cheaper to buy a guitar pick that works just as well, AND is also a fine tool for playing a guitar k thx bai
The first option also comes with a suction cup BUT here's an alternative :
