Try something along these lines:
export PS1='[\h:\u:\w]\$ '
My custom prompt lives in my .bashrc
Edit: I really would suggest keeping the \$ as it changes based on if you're root or non-root. Helps keep track, but you could put a > in instead if you really feel it has to have a > at the end. To get more or a less exactly what you want would be:
export PS1='[\h::\u:\w]> '