Greyhounds make fab pets - I'm glad you have arrived at the same conclusion 
We have had ours for over 5 years now, had him from 18/12 old, he never raced as 'too playful', read absolutely nuts!
We fostered a dog before we adopted and would have kept him but he was promised to a family with a cat as he was 'cat safe'. They are definitely individuals though - ours goes after squirrels and cats (thankfully only when he gets a chance which is, like, never and it has led to the neighbourhood cats no longer pooing in our garden. Nor do the foxes, come to think of it).
Foster dog chewed remote controls and books, DHound has never chewed anything.
Foster dog was v laid back and tolerant of all sorts, DHound can be grumpy around tall, young men ?bad experiences in his past.
Foster dog ate quite well and gained some weight from his previous racing weight, DHound weighs not a single gram more than when we got him, delisted my best efforts to feed him up a bit.
So, race characteristics are one thing, but individual dogs can still surprise you.
Go for a rescue that fosters their dogs and knows them well.
We had a crate because he was used to one. We stopped using it after maybe a year or so. Sometimes I miss it when he's booed in the kitchen.
He is nervous and absolutely terrified of fireworks, I am already dreading Guy Fawkes as he turns in to a shaking, salivating, panting, pacing wreck, even with meds from the vet.
His farts would clear whole stadiums!! 