Yeah, I don't think there's any real precedent to lean on. Historically Italians haven't settled well in other leagues, but it's probably just one of those things that will be true until it isn't anymore. Ten years ago people said the same thing about Spanish players in England and they're everywhere now.
I don't know if Izzo knows any english, but he's an aggressive, ball-winning centreback who directs the ball forward quickly. People might not think this is what we need but I fundamentally disagree. I think we need to get better at winning the ball back and quickly moving it forward. Koscielny is the only one who has done this well at Arsenal since Sol Campbell retired, and it sounds like he'll be gone this summer.
The press sometimes compares Izzo to Cannavaro, which is probably mostly because both of them come from Naples, but there's some grain of truth to it on the pitch too. I think they have a similar way of imposing themselves on the game.
He looks like he's about the same height as most of our defenders, give or take a centimeter, so ideally you would pair him with a slightly taller player. Then again we conceded 51 goals last season and almost none of them were headers, so I think height is the least of our problems right now. Izzo's got good spring in his legs too. I think he had the best (or at least one of the very best) aerial record in Serie A last year with an average of 3.3 aerial duels won per game (I just googled the numbers), and he also averaged 2 interceptions and 2.4 successful tackles per game. Those stats were from March too, and Torino finished the season strongly so they have probably improved since then.
Basically, his market value would probably be north of £50 million if it weren't for the off pitch controversy.