I don't know if any team in the world can keep him fit.
As much as he has ability, I think the fact he was screwed by that little runt Lee Johnson (who disbelieved Williams when he was complaining about a groin injury, and kept forcing him to play because various medical tests showed no evidence of an injury) has made him tentative and never quite able to believe in his own mind that he's going to be problem-free in the long-term.
When Williams gets up and running, he's great. Can play central or wide, he's decent on the ball, can cross and shoot, and he'll put himself about and press the opposition. It's never too long before he's injured again, though, and then it then takes him ages to get back to where he was. For that, I blame Johnson, who exacerbated what probably should have been a straightforward problem.
I hope I'm wrong, but I reckon you won't get 20 games out of him, and he'll be released in a year. He's a good guy, who wants to do well, and he's very talented. Made of bread-stick, Ryvita, brandy-snap, cream crackers and peanut brittle, though.