My family and I are going to be going to Yellowstone, Teton and Glacier National Parks on vacation and we would like a new camera to take along. We went a year ago with a 35 MM point and shoot and were very frustrated with the zoom. We'd like to upgrade to a SLR camera body, but don't know if we want to do digital or film. We are beginners, but want good quality equipment that we can use for a variety of photo types, as I have 10 and 14 year old kids active in sports, as well. Any suggestions on cameras, lenses and accessories (we already know we'll need a tripod)?