I've not tried to make risotto with another type of rice; I always use either arborio or carnaroli. I have, however, used short-grain or round rice in similar rice-based dishes and it worked well. This article on rice for risotto says any short- or medium-grain will work in its place. Basically you want rice that will give up a certain amount of starch, which gives risotto its signature creaminess. In this recipe, a spoonful of mascarpone added at the end also adds that, too. If you can't find it, crème fraîche or sour cream, or even heavy cream, would work, although they aren't the same flavor as mascarpone. I served this with shrimp pan-fried with butter, olive oil, and chives, but it would be good with firm-fleshed fish, like salmon or halibut. You could also serve it with vegetables, such as steamed or oven-roasted asparagus, or broccoli. If fresh peas are in season, you might serve it on its own with a few handfuls of them stirred in at the last minute.