I installed coreutils on my N800 but it was a bit buggy (seg faults with mv and ls -la)

But anyway, first you will want to install bash:
http://www.nitapps.com/

If you really do want coreutils despite the bug I said above, reply again.

(BTW, keep busybox installed. Just replace it with coreutils & bash. I've managed to install coreutils on my N800 fine but ended up reverting back to busybox. Coreutils has bugs.)