I think the greyhound idea is fantastic!
As far as show goldens- I know you're probably the last person that needs reminding of this, but have your parents be VERY careful as to who they get their dog from. There has been a slowly rising trend in SOME show-bred goldens to breed for a more intense "up" temperament (in order to make them flashier in the ring), and in SOME lines that has been translating to *aggression* which of course should be absolutely unheard of in this wonderful breed.
That being said, my next door neighbors have two absolutely wonderful (and gorgeous) goldens from well-respected programs. Their temperaments are as sweet as honey- and while they're rambunctious, they do know when to settle down and lie across your lap on the couch. Babysitting them is really a treat- can you tell I'm a tad bit obsessed?