How does 3 nights at Arenal plus 3 nights at Manuel antonio stack up for our first visit to Costa rica? Will be flying in and out of San Jose and renting car. Does this sound do-able? Wish it could be longer but time and money do not permit. Visiting in late May 2013. Suggestions for place to stay in Manuel appreciated ( near or on beach? ) Trip is myself my husband + three kids ages 19 to 25.