For me, the two that I think are legit ready are Hicketts and Sulak. Due to injuries, I voted for Cholowski to be in the opening night lineup as well.
I don't understand the people who are anti-Hicketts. I don't think he'll be a superstar or anything, but he has good gap control, makes reasonable decisions with the puck, has a high effort level, can skate and engages opponents. He wins more than his share of puck battles too.
I think Sulak is well above the pack. He skates well, has a bit of an edge, and transports the puck well. He is sometimes a bit loose with his passing but I think that'll settle down.
For me, both Cholowski and Hronek would benefit from time with GR. Could they play in the NHL right now? Yeah, sure they probably could but I don't know how well they'd fair. They'd probably do all right. But I think with more time in GR when they eventually come up they'll be further ahead