I don't think Parayko is a good target for the Oilers.
Not because of his talent. He's a big, steady, defensive minded guy who eats minutes successfully against other teams top players. But the contract is what kills this.
6.5 for another 6 years for a guy who while is still excellent, has seen a ton a heavy mileage and had some crappy back issues to boot. Not saying the wheels will fall off overnight, or even at all, but it's just a long term risk that could seriously hurt their cap flexibility with a ton of important contracts coming up. Plus if him and Ekholm both hit a decline, that's massive money tied up in heavily worn albeit solid defenders approaching the tail end.
Heavy gamble for Edmonton and the cost would be huge to acquire him. They aren't retaining.
Doesn't work at all with the cap.