All the HPR breeds can be used, although some take to it better than others, the GWP is better equipt with haveing a better jacket, although it may not be the best choice for someone looking for a first time dog, i have had both and will be having another GWP in the future but if i was you i would go for a lab mate, easy to train and biddable.
Good luck and let us know what you choose.
Dave.