I had a Trailgator and hated it. It was so unstable and just had too much play in it to be safe. Honestly any trail a bike brand is better and safe than the Trailgator. I have used Instep/schwinn, Weeride and my favorite is Adam's. I think Adam's is better, but honestly all of those are acceptable alternatives.
The buddy bar thing is only sold on Ebay as far as I can tell and that makes me even more concerned about the safety aspect. I have tried to find review and thought maybe it was sold in a foreign country, but info just doesn't seem very available. Based on the pictures, I would say that it has just as great a chance of being unstable as the Trailgator. Thus I would recommend staying away from it.
Trail a bike are readily available on nearly all craigslists. Maybe that would be a good inexpensive option.