There are a wide variety of vegetarian ham and bacon substitutes. None of these are exactly the same as bacon or prosciutto, but any of them would work, though you may want to add some more oil/fat to the party, since they are generally going to be low-fat.
Here's a detailed thread on vegetarian/vegan bacon substitutes.
To summarize, you can add smokey flavor to a variety of vegetarian proteins or vegetables with a chewy or crispy texture. These include tempeh bacon, tofu bacon and coconut bacon, all of which are relatively simple to make at home. Additionally there are commercially made substitutes including Lifelife's Smart Bacon, Morningstar farms veggie bacon, Lightlife tempeh bacon strips, smoked tofu as well as various brands of Baco's or Bacon Bits. You generally add smokey flavor one of three ways - liquid smoke (easy and potent), smoked paprika (more expensive, less potent), actually smoking the ingredient in a smoker. I've also seen recipes where people smoke mushrooms and use as a smoked meat replacer.
There are also a lot of vegetarian ham substitutes including Lightlife Smart Deli, Yve's Deli Slices and meatless Canadian Bacon, and others you can find at some Asian markets.
If you want a less smokey flavor, but a similar texture you could use baked tofu (maybe flavored with miso, soy sauce and/or seaweed for umami flavor), or seitan.