My husband and I are going to Costa Rica for the first time in mid-April. We are planning on having a rental car and driving from the airport in San Jose to Jaco where our hotel is- is that a good idea to have a rental car (we like to do things independently, and have driven in Europe, and my husband has driven in Australia and Africa, so if it's less complicated than that, we would like to have our own transportation.) Also, we would like to plan some white water rafting, zip lining, possibly surfing, and we would like to go to the M.A. National Park and the Arenal volcano... any suggestions where to go through for the first 3 activities, and any other things that shouldn't be missed? Also, do most places take credit cards, or what form of currency would be best??