Finding The Best Kitchen Knives

Recommendations for Sushi knives?

I have most of the apparatus to make sushi at home, but I am lacking the proper knives. Since I am still a novice, I'm not willing to spend a lot on the necessary knives (I am not a professional chef either), but I do believe in getting a quality product the first time.

1) Which knives are (most) essential for preparing sushi (maki & sashimi) and what are the purposes of each?
2) My regular kitchen knives are Wusthofs - can I use any of these? (maybe the cleaver or parer?)
3) Which Japanese line/manufacturer of knives are recommended?

Thank you!