I don't believe that all things are in the same place as they are on a standard PC Linux install

There is a standard place for things in the Linux world between all the distributions?

Honestly, installing Fink on a Mac gives you even more of the Unix type enviornment to work in. The advantage of a Mac these days is you can poke at the Unix layer under it, while still having a good work enviornment at all times. Plus, Linux can install onto a Mac and coexist with OS X if you want the full Linux feeling. It's an expensive route though, but may be worth it as an overall platform switch.