I get my Tofurkey Italian Sausage at Trader Joe's, since it's so inexpensive there, but I've seen it at Wegman's and Giant, too. Look in the refrigerated natural foods section.
I think making this with the pesto was a great decision, and I'm going to keep making it that way, and drizzle the tomato sauce over each serving. Mmmmm, I'm already looking forward to a piece for lunch tomorrow.