You can get all these tools easily from the Anaconda Python Distribution, which is free, well supported,and includes all packages mentioned plus way more, including things like scikits learn. I work for continuum
$ python --version
Python 2.7.3 :: Anaconda 1.4.0 (64-bit)
It installs to a directory so you basically just add it to your path to get it working it doesn't change anything else on your install.Beware though that you don't use virtualenvs with it but you use their tool conda to create your environments
conda create -n py3 python=3.3 anaconda
conda create -n py27 python=2.7 anaconda
That will create environments envs/py3 and envs/py27 inside your anaconda install directory.