Don't get too caught up with a set amount of time. As rice ages it continually loses moisture and becomes more dense/harder to penetrate with moisture (same thing with dried beans). I've used really old arborio rice that tooked 40 minutes before it stopped being crunchy. The only way of knowing is to watch it and continuously taste it. And, don't forget, it'll continue cooking a bit after you take it off the stove. It'll also continue to thicken a bit/absorb water as well, so make sure it's pretty loose when you remove it from the heat. Getting the right amount of liquid in the final plated dish is a little tricky. It's very easy to have it end up dry or soupy. And, as I'm sure you're aware, the timing is critical for serving it. The right creamy texture at the right eating temp, takes some work, but when you achieve it, it's a magical eating experience.
I'll second the Parmiaggano Reggiano endorsement. It makes the dish. Also, the chicken stock has to be homemade. Has to be.
If you can, have extra stock simmering. It's very easy to misjudge the liquid needed and run out. I don't have any hard evidence on this, but I believe that adding water at the end gives you an inferior product to diluting your stock at the beginning of the process. That's my theory.
And lastly, unless you live in a cold climate or have a phenomenal ventilation system, I'd wait a few months for risotto. I sweat like a pig when I make risotto, and that's during the fall/winter. I won't even try making it during the summer.