I am not a historian, so I don't know how much my help will be truly helpful and competent, but I'll give a try. If by primary sources you mean original documents in digital format, I fear I could be quite difficult to find them. Given the span of time you are considering (XIX century) I doubt that there exist collections of documents concerning the Italian Risorgimento in English. As far as I know, the only collection of historical documents available on-line refer to the XX century and usually they are related to large institutions (I'm thinking about the FRUS - Foreign Relations of the United States, available on-line, or the digital archives that have been prepared by the EU, see for instance the CVCE). I mean, to find original documents in digital format on-line could be difficult even if you are working on the XX century.

While If you are looking for works/books written by key figures of those years, yes, you should be able to find some books in English (but much more in Italian). See for instance:

G. Mazzini, Selected Writings, ed. by. N. Gangulee, London, Drummond, 1945

---- A Cosmopolitanism of Nations, Giuseppe Mazzini's Writings on Democracy, Nation Building and International Relations, ed. by S. Racchia, Princeton UP 2009,

C. Pisacane, Revolution. An Alternative Answer to the Italian Question, ed. by R. Mann Roberts, Troubador, 2010.

You can see also the biblographical essay cotained in D. Mack Smith, Mazzini, Yale UP 1994.

And very likely you should be able to find some works by Carlo Cattaneo and Cesare Gioberti also in English translation.

What I would suggest you is to carry out a bibliographical research on English critical essays about the topic. In these books, the authors may refer to primary sources either in English or Italian. Or you can try to have a look at Italian primary sources (in that case libraries have plenty of material!).

Best regards and best of luck

Tommaso Pepe

Florida State University