If you can, avoid the wrist device. Nothing beats a free hand, and a wrist support does not prevent you from topping the ball or cover up release flaws. Better do some wrist training to build strength - takes some time, but it is IMO the way to go. Or invest the money in a coach to get the foundations right.
A wrist support can be a help with your injured wrist, though (wore one myself for a year because of a bowling injury), but then I'd suggest talking with a coach or a good pro shop who knows your game to find a model that is as light as possible and actually helps you with your injury - just do not buy the first best thing in the shelf. If you can, try out one or two models to see how it fits and whether it actually helps.
--------------------
DizzyFugu - Reporting from Germany
Confused by bowling? Check out BR.com's vault of wisdom: the unofficial FAQ section