Hello everyone, I am interested in purchasing a used/refurbished mac. However, I don't know what model to get. I want to pretty much use it to learn OSX, browse internet, use apps, and my wife will probably use it for small graphic design projects. What would be the best model to get? I would also like it to be powerful enough to be able to run Tiger when it comes out. I was thinking that anything below a G3 wouldn't work. Any suggestions? Thanks!