You would want it to be dismissed with prejudice so that it cannot be filed again (even though chances are unlikely because the attorney wouldn't likely agree to dismiss if there was a reason to think a judgment could be had). It wouldn't hurt to have a consultation with an attorney to look it over just to make sure you aren't missing anything.
Definitely seek the advice of an attorney in Arizona. The NACA lawyer database is a great place to find a consumer lawyer who can help you.
A dismissal with prejudice means you cannot be sued again on that debt and probably have the right to remove related information from your credit report.
A dismissal without prejudice means you can be sued again and you have no right to remove related information from your credit report. Although chances are often good they will not try again if you accept a dismissal without prejudice, there are no guarantees.
In your situation, try to get the case dismissed with prejudice so that you know that the case is dead forever. If it does not state it is dismissed with prejudice, the lawyer can refile the case later.