I like Vivian, but the Lake part is on the cheesy side. The combo makes me think of Vivien, the Lady of the Lake, which is an association that I like, but VivianLake just doesn't do much for me.
The Lady of the Lake is named Vivian (at least in some versions). It also sounds a bit like VivienLeigh, which was what I first thought when I read the name. There's also VeronicaLake, so a combination of the two actresses' names?