I'm selling my second hand paddles at the mo, but I think they'd be too short for a guy or a goalie, unfortunately.
I'm sorry you had problems with your Double Dutch- I have paddled with Double Dutch for years and I LOVE them. I'll be sorry to have to sell them. I had the shaft replaced because that fell apart one day when at an NZ training camp, and other than that, I've used those paddles to death and they're still going strong.
It does sound like the sets you've been given are inferior, and without seeing your style of play, (let's face it, that sounds like someone who played polo has told the shop to say that, because they're not watching you play or saying anything specific) I think I'd be pretty insistent about a new paddle blade lasting the distance. After all, my Double Dutch set have been going for years...