dang I am very sorry to hear about the loss. There is something about loosing a stingray that has always affected me more so than most any other fish.
A hystrix would be a great ray. They seem to hold up better and demand a higher dollar amount which usually means they get better care along the road prior to your purchase of the ray. They also stay smaller which makes them a more tankable fish.
Sorry again man that is a real bummer, best of luck for your buddy next time