I'll assume that by "pre-unification" you mean in the period between Napoleonic Italy and Italian Unification; although the Italian States created by what is more widely referred to as "The European Restoration" were the successors of polities with long and storied histories. But I'm also not entirely sure what sort of "views" or "stereotypes" you're looking for. Much of travel as we would recognize it, both for leisure and migration, wouldn't become widely accessible until industrialization, notably steam power, became widespread and commonplace (in other words, after Italy's unity). That's not to say there wasn't any travel at all, Italian ports were major mediterranean centers of shipping afterall, just that I've never really encountered mentions of "stereotypes" before cross-culture contact became easy, or notions of distinct national identity definitively and distinctly emerged in all of Europe at the end of the 19th century (as opposed to local, more tangible identities). In short, the "us versus them" mindset that needs to exist for stereotypes to exist needs an "us" before it finds "them," and this sort of mentality didn't really flesh itself out everywhere and at the same time. Things would of course change with mass migration, mass media, and the consecration of nationalism as a major driver of the interests of states; and although those things were certainly already emergent in some places in the immediate post-Napoleonic world, one of the last places where they would come to exist would be Italy.

The most common commentaries left would be by those whose job was to travel and report on their surroundings, typically diplomats and statesmen, but I don't know if they were representative of commonly held beliefs such that they constituted "stereotypes." For example, the British Prime Minister William Gladstone published an editorial on the political situation he saw during a diplomatic visit to Naples which you can read here, but this is of course not representative of the thoughts of the whole of Britain, nor representative of what Gladstone might have thought of the rest of Italy; indeed Gladstone's thoughts on the Kingdom of Piedmont-Sardinia were much more nuanced, however these too must be framed within the wider context of the ultimate goal of preserving peace in Europe (under threat given Piedmont's stance against Austria) and not some preconceived notion on national character such that it might be called a stereotype. And lastly, Gladstone's thoughts can't even be said to be representative of the rest of Europe: one of France's greatest diplomatic triumphs is turning the Kingdom of Piedmont-Sardinia to the French sphere and sparking Piedmontese conflicts with the Austrian Empire. Although a logical turn of events in hindsight, especially given the shape of intellectual life in Piedmont, the Kingdom of Piedmont-Sardinia was originally conceived as an Austrian-aligned buffer state between France and Austria, rewarded by the Austrian foreign minister Metternich for its monarch's staunch anti-Napoleonic stance with an expanded terretory; few would have foreseen that less than two generations later a Piedmontese monarch would align himself with a new Napoleonic Empire against Austria. And as a consequence the Austrian government's stance, and Metternich's stance, towards Piedmont would also change.

In any case, my point is that collecting the entirety of foreign positions on the governments and people of pre-unitary Italy a long and difficult task. You might be better off looking into a more generalist history and taking ideas from there; Italy in the Nineteenth Century by John A. Davis is a great place to start. But if you're interested in personal opinions to see what some "people at the time" might have thought, you might be interested books which, while not representative, were certainly somewhat influential and widely read in their day: the french writer Stendhal, who lived in Italy several years, completed Rome, Naples and Florence in 1817 which you might be interested in. The book is an example of a person's impressions of a large part of Italy in the aftermath of the restoration (and certainly more positive than Gladstone's view). Another interesting travelogue written when the unification process was underway (the nascent Italian state had absorbed everything but Rome) are the parts of Mark Twain's Innocents Abroad which take place in Italy (although it's mostly written to be humorous and is very superficial, I can't help but feel that modern tourists' take-aways aren't that different).