AR ES-1 table w/AQ tonearm

Hi all,
I just inherited an AR ES-1 turntable with an Audioquest tonearm installed from a buddy. First of all, is this a decent tonearm? Is there a better alternative for not a load of money? I currently run a Pro-Ject original Xpression. Is the AR better? And lastly, I need a new belt for the AR. Is there anyone that still carries parts for the AR?
Thanks