...How I'm setting VIM up now...

First

I just use oh-my-vim.  Its like oh-my-zsh, so it gets you package managment and highlighters and so on, for free.

Then

NERDTree! Since oh-my-vim gives you NeoVundle, you can easily do :

:NeoVundleDirectInstall 'scrooloose/nerd-tree.git'  # or whatever